I was wondering how much you are using your Steam Deck? And did the games you play on it change since you bought it?
I find that I used it a lot when I first got it, but my usage has gone down in the mean time. That’s mostly because I play games that are not a great fit for the Steam Deck (strategy, building, etc.) and I prefer to play those on my PC.
My previous PC that I used until Nov 2023 was build on even older CPU in 2013 (Haswell), but has a 1070 and 16gb RAM. I directly upgraded from 750 Ti > 970 > 1070 and stuck with it. :D But also I was playing on 1440p and if possible at 120 fps. So my assumption is you play on 1080p and most games (maybe besides the newest hot AAA) should run fine at 60 fps if you lower the settings. We even have upscaling nowadays!
I know what your system is capable of. It’s a little bit on the edge now, especially the CPU was holding it back for many other areas as well, but, as you said, it holds up suprisingly well given how old it is. The 900 and 1000 GTX series is probably the best graphics card generation we ever had (9 and 10 series are based on the same tech I think).
Happy cake day (I talked/wrote too much, was just thinking out loud, got kind of nostalgic lol).