I wouldn't take all figures from the NES era as gospel, the game industry was the wild west back then, sales figures weren't accurately kept especially for 3rd party games, many of these companies don't even really exist anymore. 

I do think Nintendo did share 1st to 3rd party splits for hardware, that would be a better gauge, but the NES had a massive, massive amount of its software sales from third parties. 

Even things like 'Nintendo franchise' weren't as pronounced of a thing back then, people have to understand there was no such thing as Mario Kart, Pokemon, F-Zero, Animal Crossing, Smash Brothers, etc. etc. etc.. The only "franchises" Nintendo really had were Super Mario, which was a Ninja Turtles sized phenomenon in itself, and then Legend of Zelda which wasn't on that same level. 

But things like Punch-Out, Kung Fu, Duck Hunt, Ice Hockey, Metroid, Ice Climbers, etc. weren't really "franchises". They were just at that time one-off experiences for all anyone knew. Donkey Kong was out of style by then, a relic of the old Atari 2600 age of non-scrolling games your old uncle liked, Donkey Kong wasn't cool anymore. 

That was actually a big thing back then, being a "Nintendo fanatic" back then meant you weren't just good at Super Mario Bros. ... that was like "so what?". Everyone could play and beat Mario. If you were "big time" it meant you mastered a wide variety of games like Megaman, Castlevania, Blaster Master, Wizards & Warriors, Ninja Turtles II, and if you were really hardcore, even more niche style games. 

The NES era was just different. There was a magic of discovering new games and trying to "figure them out", calling Nintendo's hotline when you got stuck or digging through pages of Nintendo Power. No modern Nintendo system is really like the NES even though people want to try to shoe horn that comparison badly. The Wizard movie (a film basically designed by Nintendo's marketing department) from 1989 actually encapsulates the NES era reasonably well:

Nintendo's marketing department of the day also makes it seem like basically all video games, even arcades were all "Nintendo" (even though things like Megaman 2 weren't available in arcades), which was actually a fairly commonly held belief by a lot of parents. Video games were all just "Nintendo". 

PS2 happened.

The Xbox had 8 texture mapping units. It's Geforce 3/4 derived. It can match the Gamecube on this front.

Though the OG Xbox can handle larger textures due to it's higher system bandwidth and system memory capacity... The Cube had the texture cache and 1T-SRAM to make up some of that difference and can simply sample more textures and layer them appropriately in real time.
Star Wars definitely showcases this advantage for the Gamecube to a great extent.

Definitely. The Gamecube's TEV meant it was a texturing powerhouse, no doubt... And the games showcased that.
But for compute it was a no contest, this was simply one of nVidia's big key strengths at the time, no one would approach nVidia on this front (And we aren't talking raw specs here, but real-world capability) until ATI brought out the Radeon 9700 years later once the 7th generation was underway.

The Xbox being built on PC technology had a more 7th-gen hardware design which emphasized shaders and compute to pull off effects like deferred rendering in Shrek (Something that hit it big with Battlefield 3 during the 7th gen)...

And Ray Tracing in Conker: Live and Reloaded. (Global Illumination.)
In Conker if the normal looks towards the ground, the engine would shoot a single ray from the sky towards the ground and do collision detection with colour encoding calculations performed on the vertices.
Result was the ability for the engine to seamlessly do colour shifting between scenes.

Obviously Conkers implementation of Ray Tracing is rudimentary as it's only running on 6th gen hardware, but hard to ignore the benefits it brought forward.

Since then Ray Tracing has only become more intricate, demanding and impressive.
Conker and Shrek though are probably two of my favorite games that showcases the foundations of the main technologies we rely on today and which define current games and rendering approaches.

It was really forward looking hardware.

The XBox kind of screwed things up too .... if there was no XBox or it fizzled out quickly like the 3DO and Jaguar did, the GameCube probably sells a more comfortable 40-50 million units.

They would've gotten beat but it would've been more respectable of a gap I think as with Sega out, GameCube would've been the only other alternative to the PS2 and since it was quick to $99-$149.99, it would've been cheap to pick up as a secondary console.

The GameCube still did have some good things going for it, game droughts were not nearly as prevalent as the N64, Resident Evil was exclusive which was a huge get at the time it was like getting the 2nd or 3rd most popular 3rd party IP exclusive.

In hindsight with the GameCube, knowing what we know now, I would probably tell Nintendo of the late 90s ...

- GameCube has to launch in late November 2000. Fall 2001 is too late, lets Sony get too much of a head start and lets Microsoft get their behind schedule XBox into the mix.

- The purple Fisher Price plastic design needs to go. Make it look like an Apple product or ditch the cube design entirely.

- Mini-DVDs are out. Full sized discs. DVD playback is optional via plug in dongle, so Nintendo can off-load the DVD licensing fee costs.

- Zelda: Majora's Mask, Perfect Dark, and Conker's Bad Fur Day are off the N64 and launch window GameCube software. To play basically any of these games you need the RAM expansion pak anyway ... hire extra artists if need be to work double time to bring the graphics performance up to snuff. N64 becomes more of the kids/Pokemon spin-offs machine in the later years of its life.

- Mario Sunshine time is given more time to bring the game up to a higher level. 

- Controller is tweaked, d-pad is larger, L and R buttons.

- This is probably cheating, but buy Bungie/Halo IP before Microsoft does, lol.

I actually remember reading about how Battlefield could have been a Nintendo exclusive, originally. It's not exactly the same, mind you, especially since Battlefield didn't make it big on the console scene till Bad Company. But it's interesting nonetheless! Nintendo could have had their Splatoon/Halo much sooner. That's assuming that everything went right, of course, which isn't realistic, but still fascinating!  

Eh Melee outsold Halo and Melee made the Smash series the phenom it would become,while Halo is now limping along hanging onto former glory. If Gamecube had a competent online service like SEGANET or XBL along with Melee having an online mode. That would have been something.

The GameCube didn't fail the market. The market failed the GameCube.

It is still my favorite console of all time, with my favorite list of games ever. It was powerful, it was portable, it had the GameBoy Advanced adaptor (that I used a TON), and it had the best controller of all time, across any system. Smash Melee, Luigi's Mansion, Animal Crossing, Pikmin, Metroid Prime, Twilight Princess, Paper Mario TTYD, Rogue Squadron II, and so, so many more. It was a gamer's dream, but sadly it was destined to fail because everyone got obsessed with having DVD players built into everything. We were stupid and so the greatest device ever failed.

I agree, to a certain point. I still think some of Nintendo's decisions like the mini-DVD were very stupid. But I'll give Nintendo a slight defense that the 'Cube was only $99.99 from September 2003 onward. That is super cheap for a current-gen console a little less than two years after its launch. 

If Nintendo would've launched the GameCube at $99.99 or likely $149.99 and changed virtually nothing else, I do think it would've sold at minimum the same lifetime units of the N64. Heck, it might even match or surpass the SNES.

You're at the store. You're getting a new game console. PS2 is $299.99, Xbox is $299.99. But the GameCube is half the price. Sure it doesn't have a DVD player or online, but you have a pedigree of Nintendo titles and some multiplats. It would make a very attractive option for kids and adults alike.

Fun fact: Europe received roughly 600 fewer Game Cube titles than the USA.