The Switch still seems fairly new despite reaching the four year mark. I didn't feel that way about other recent Nintendo systems, like Wii & 3DS at their 4 year marks (and of course the Wii U as well).

I'd probably give the Switch a 10/10 and maybe it's my favorite game system of all time. It does have my favorite 3D Mario, 3D Zelda, Smash, MK & Animal Crossing games. One big thing that kind of sucks (for me) is that I don't like the main series Pokemon games on Switch compared to prior entries. Might even skip DP remakes (ironically, Pearl was the first Pokemon game I preordered). Still though, the system seems to be doing great on almost every other front and still looks to have big games left to be released. I do also wish that their digital library of older games was better and extended past NES & SNES.

Imagine the Series S was Nintendo's next console. For $299. We'd all be happy. If Wii U games had been ported to be 4k/60hz on Nintendo's Series S, I'd have been happy, instead of just Wii U to Switch games barely improved, I would have been excited. Hopefully Nintendo still has a future product for me. Someone that has been waiting since the Wii U died to get excited again.

While I can definitely understand the appeal that a dedicated Nintendo console on par with Xbox/PS has for a lot of us, I don't think it would make much sense for Nintendo; the whole point of the Switch has to unify their production pipeline and console/handheld divisions into a singular piece of hardware. To now make a separate console on par with Series S would require a ton of R&D, and undo that unification, meaning less games and the same droughts that crippled Wii U.

I think it became unified because portable hardware became faster relative to home hardware. Even if they had a Series S device, you can still consciously choose to unify your software platform, since it takes 18 times more GPU performance to get from 720p/30 to 4k/60, there is still much to offer people in terms of upgraded Switch visuals while still having a base Switch game.

What you said earlier about your "experience matters" is so true. For example I paid a fortune for Virtual console titles on Wii U. Still use it all the time. Not only did my purchases not carry forward, I can't even buy most of them for Switch. Zelda: Minish Cap!!!

Meanwhile my Xbox / 360 / One / and Series X purchases are all shared...

Yeah the way Nintendo handles retro game right now is atrocious.

As to a Series S like dedicated console that would play Switch games at 4K, would that sell enough to justify its costs? I don't think it would as the hybrid concept is such a key part of their current hardware's appeal.

If the Switch would have been a Series S like console instead, Nintendo would be dead (or close to it). Switch sold 80M units. A series S like console would be sell far less, as we see - well the Series S. While some Nintendo fans would be pleased to play their favourite games in 4K, the console wouldn't have catched on fire with the overall population as much as the Switch did.

That's not true, that's just empty speculation. Nintendo hasn't made a normal console since the Gamecube era and they were facing the DVD juggernaut that was Sony.

Also nobody said you can't have a Switch and a Series S style console for playing Switch games at 4k/60 at the same time.

The last times Nintendo tried the route of "Nintendo games in never before seen quality": Gamecube and WiiU.

The Switch on the other hand is on it's way to beat Wii and PS4 and becomes the 3rd best selling system of all time.

And the two power options - how does that work out for Xbox Series so far? Has it ever worked in the past?

I think someone said it earlier but it's strange, Switch feels so young for a system that's been out more than four years, and I mean that in a good way, it feels like it could easily go another 3 years or even more.
Normally when a Nintendo console's been out for 4 years, it's getting close to the end of its run.

Let's see:

SNES - Turned 4 in late 1994 (Japan), mid 1995 (NA), early-mid 1996 (PAL) - Notable games: Original DKC trilogy, SMW2: Yoshi's Island, Killer Instinct, Dragon Quest VI, Chrono Trigger, Super Mario RPG + a lot of high quality 3rd party titles. And with hardware sales still relatively steady, enough to breakaway from the Genesis and win the 16-bit Console Wars and had a great sendoff before the N64 arrived. Yep, Super Nintendo is still the king. (For now)

N64 - Turned 4 years old in mid-late 2000 (Japan and NA), early-mid 2001 (Europe and Australia) - Notable games: Majora's Mask, Conker's Bad Fur Day, Banjo-Tooie, Pokemon Stadium 2, Paper Mario, Mario Tennis, and Mario Party 3; Pretty solid list with a strong first few titles, including what I consider the best 3D Zelda game pre-BOTW. But that was about it, aside from the few 3rd party games it received that were far better on the PS1 and Dreamcast anyways. And sales had dropped drastically at that point with just 1 year before the GameCube came out, so not what I'd consider a good life post-4th year.

GCN - Turned 4 in late 2005 (mid 2006 in Europe and Australia) - Notable games: Twilight Princess, Pokemon XD: Gale of Darkness, and Mario Party 7; ...Damn, that's pretty pathetic. Nothing against those three games. I love Twilight Princess to pieces, but it was also the Wii's launch title so that weakens the impact for the GameCube. Never played Gale of Darkness or Mario Party 7, so I can't comment on those. But you could tell Nintendo gave up on the GameCube at this point and they were chomping at the bit to move on to the Wii.

Wii - Turned 4 in late 2010 - Notable games: Skyward Sword, DKC Returns, Return to Dreamland, Xenoblade Chronicles, The Last Story, Sonic Colors, Mario & Sonic London Olympics, Mario Party 9, and a crap ton of 3rd party titles (even if at least half of them were shovelware.) Another solid list and I'd say even stronger than the N64. I guess the Wii had a better last few years than I originally thought it did. Now that I think about it, maybe they should have rode the Wii for another year so that they'd have time to make sure the Wii U's launch lineup was strong & loaded, and so they could iron out the kinks and fix easy mistakes they made early on (like the name and marketing.) But then again, if they did that, we'd probably have no Switch right now, or at least not until just very recently. So perhaps it worked out better this way.

Wii U - Turned 4 in late 2016 - Do I even have to say it?

TL:DR - It seems like ever since the Super Nintendo, the last one to still have a strong and healthy life post-4th birthday, every other Nintendo console noticeably dropped off in terms of sales and software releases. But the Switch looks poised to break that jinx and really flourish in the 2nd half of its life. (Provided Nintendo doesn't screw it up, which they unfortunately have a habit of doing.)