Not sure if that's true. The ps4 sold 14,6m in 2014 and it makes sense that people are now waiting for the ps5/Scarlett instead of buying a ps4/Xbox. Obviously Nintendo has its exclusives that are its major draw but we've also seen that Mario and Zelda alone aren't enough to guarantee success next gen, if you look at what happened with the Gamecube and Wii-U. Besides, Sony has arguably the better and more varied exclusives.

To me the success with the Switch lies in the fact that it's a handheld with pretty impressive graphics at this moment. However, when the next gen hits, Switch graphics will look seriously more dated and support from 3rd party developers will be non-existent. Sure, you can say 3rd party games don't tend to sell on Nintendo consoles but that doesn't mean they don't need it at all. 

PS4 sold 20 million units in 2016, so it took a couple years to reach it's peak selling power.  I can't find the data at this moment but if memory serves correctly the PS3/Xbox 360 still sold extremely well during the PS4/Xbox One early launch years (like 15+ million units per year).  Historically speaking next generation consoles take a couple years before peak sales are attained. The GameCube and Xbox were dominated by PS2 in their respective generation.  The Wii U was a marketing disaster and was a failure before it even launched.  There is still people to this day that don't realize it's a different system from the Wii.  And Nintendo has way better and varied exclusives.  And just to be clear, 3rd party developers needed the Wii, not the other way around.

The success with the Switch has nothing to do with graphics.  It already looks extremely dated compared to One X/PS4 Pro and yet still crushes sales.  It's games are crushing other games at the moment.  The Switch has shown that having the most powerful graphics doesn't matter to the majority of buyers, if it was it would have failed just as bad as the Wii U.  People want good and fun games, there is only so many times you can play CoD clones and adventure games like God of War/Fable before it becomes super repetitive and "boring".

...because?

Makes sense. I think the PS5 will be a force to be reckoned with though. The PlayStation brand is still the biggest one in the industry and Sony are great (and one of the very few) at making AAA games without having the 60$ be the starting point and not the final price. MS will still be chasing Gamepass and microtransactions together with their bff EA.

I don't know if I would call PS the biggest brand... Nintendo's best games usually outsell PlayStation's best games (speaking about exclusives) by almost 2 to 1 and don't ever drop their price while maintaining those numbers.  And if you take the Combined hardware sales Nintendo has a larger saturation than Sony (and that's with Switch being around for a less time) this generation (PS4 + Vita is about 120.49 million units, 3DS + Wii U + Switch is at about 134.85 million, minus Wii U it's at 120.88 million).

EDIT: I have no idea what to make of Microsoft of the upcoming generation.  They were headed in the right direction during the Xbox 360 era but the Xbox One era has really set them back.

True, but Game Pass is not very good for anyone in the industry except for MS and publishers of failed games that MS might give a very small share of their profit. Its great for gamers at the moment, but look at how much better games sell on the PS4. Even with the install bases considered, its still insane. 

Well it is the brand that is the most consistent. Nintendo keep rebranding their consoles and handhelds.

I don't know. I mean games can and will always look better but (to me) the 8th gen had the smallest leap in graphics ever. I feel like 9th gen gaming will be there same outside of VR. I don't want to downplay frame rate and resolution but I feel the Switch will be capable of compelling visuals for at least a couple more years. Besides, the selling point is the concept, not the power.

I do worry about "what's next", though. Nintendo is going to have to come up with some new idea with their next hardware. I don't know what that could be. Hopefully not another Wii U misstep.

Well Steam and Game Pass are two very different things. Even if you do a discount on Steam, you still get money and you do have the choice of how much to discount it. Im not sure how Game Pass work, but Im guessing you get paid a fee upfront for your game and that's it. Now it doesn't matter how it fares and the physical and digital sales of your game will tank. Then people will just expect games to show up on Game Pass and not bother to buy games new. That will hurt MS a lot. I don't think they can support Game Pass and have a platform for third parties to thrive.

Nintendo is the "brand".  I have a feeling though that the Switch brand is going to be the future for them going forward (Switch 2, Switch Pro, Switch Lite, etc) and they have learned their lesson with the Wii U.