There's definitely some things that won't run on it, but mine is 2 years old now and it'll play Cyberpunk, RDR2 & Elden Ring at a locked 30 no problem. Everything is on Low, pretty much, but I'll be damned if I could really, earnestly spot the differences between that and High/Ultra on my gaming PC.
But I tend to play way more indies and old stuff anyway, so it doesn't really need to be amazing for me either. Skald has been great to play on it and it's my preferred system for it.
Aside from what I already mentioned about the Deck and the touchpads, I'd trust Valve more than the other manufacturers. Ayaneo isn't bad, but they have similar issues to the other Chinese handheld companies in that their QA and customer support is middling, at best. Granted, I haven't read any recent reports about their stuff, but I'm "into the scene" for lack of a better term and a lot of the companies, Ayaneo, Anbernic, Miyoo, Powkiddy, etc, have issues with screens falling out or the adhesive letting go. My Miyoo has this issue and while I can just push it back in, I wouldn't want to spend more than the $50 I did on the thing.
Then you have Asus who is already releasing hardware upgrades, which I suppose isn't too far out from the Deck OLED, but it seems to me that Valve has a vested interest in keeping all their devices going and trying not to give people the "wants" for new devices, since they make their money on the store and not hardware revisions.
Not to sound like a Valve shill, I just haven't seen much else that I'd even consider replacing my Deck with. The only one I'd consider (if I could even afford it) might be the GPD Mini, because it has a keyboard and whatnot. In my recent travels I've found myself traveling with my Deck and my laptop, just because the laptop is easier to use when I want to relax and watch YouTube or surf the Internet (does anyone still say that?). Deck works well for pairing a Bluetooth keyboard and mouse too, but it just won't replace my laptop for convenience and versatility.