I’m the same: I used it a ton when I first got it and now it’s collecting dust. Here are my personal issues with it:
I find it a little too big and bulky for 2D, retro, and lo fi games, but too low res and weak for a good experience on most larger/newer 3D games.
The controls and screen size/res are not adequate for most PC mkb oriented games.
The size, battery life, and low screen visibility in bright places make it not worth traveling with compared to my Switch.
I guess I essentially just wanted a Switch that could use my Steam library for 2D indies and older games.
Aside from that, I think I also kinda bought it to rejuvenate my interest in gaming, but it only did that for a few months. That has nothing to do with the Deck though.
Yeah, that last part about getting my gaming vibe going is something I recognize. I used to get a lot of joy out of gaming and could spend hours on it. Now it is feeling more and more like something I do just to pass time.
I really like the dumb detachable controllers on the Switch. I love that form factor. I wish I could play 2D or low res Steam games on the Switch. But I don't really want to buy a Switch without that, and the hardware is kinda underpowered, and there's no Linux support that I know of.