Turning old (beginning of middle age) has really messed with my perception of forever (or "ages" in this case) how long has it been out, 5 years now? That seems like not too long of a time.
The Dreamcast was released almost exactly 25 years ago. That's the difference between the end of Gerald Ford's presidency (what would have been Nixon's second term) to 9/11. So I don't know what time warp you fell into.
In real time it's been longer than it was from NES to Super NES. For the teenagers clearly doing most of the commenting on these Nintendo posts, they were in elementary or middle school at launch. Now they're in college.
I'm right there with you, my deck, and my future deck 2 (there will be no deck 3 because valve/steam/GabeN) is probably the only "console" I get from here out
I have emulators from Atari 2600 to N64 installed currently, and they all run well. Haven't tried any GameCube+ emulators yet, but I don't think it would have a problem. I've seen videos of people running TotK with a better frame rate than on Switch, but I don't if that was "out-of-the-box" or if they had to tweak things.
Either way, it's a damn capable device for the sub $300 it's on sale for right now. (Base model, of course) I've been thinking of upgrading to the high end OLED model.
I waited a year after release before I got mine, and I should have gotten it day one. It pretty much goes everywhere with me, and I already had a Library of games thanks to years of Humble Bundle purchases.
Games go on sale dirt cheap constantly as well. If I never bought another game, I probably have a solid 10 years of things to play, but I have a bad habit of buying bundles because there's 1 or 2 games I want and I end up with a dozen for "free."
It requires a bit of tweaking to get TOTK to not be locked to 30fps. I'm not sure if a Deck could get a solid 60 in it; it still takes a bit of a beast to do that. But running it at the normal 30fps is easier and somehow it still looks smoother than other games at 30fps.
GameCube and PS2 games work incredibly well on the Steam Deck. Some PS3 and Xbox 360 as well. I've played through several PS2 games and all of TLoZ Windwaker on my deck.