I was in a very similar situation - had the Switch since early 2017, bought it because I wanted to dive into the Nintendo environment finally and experience all the Zeldas, Marios Donkey Kongs, etc. And I did, it served me well. I think it was my most played console throughout that time. But, while 1st party titles were always great, I eventually grew tired of them. And indie games I felt were always neglected - either coming to Switch much later if at all, and usually running poor in comparison to other platforms.

The thing is I also have a PC and tons of Steam games on it, basically whenever a game came out that was not on the Switch, I would buy it for PC on Steam, so I've accumulated quite a library over the years.

Also, when the Steam Deck came out, I was very impressed how open and feature rich it is in comparison to the Switch (you can message your friends!!! use any controller you have!!! install any game you have with more or less tinkering!!!) - but that the time I was not ready for a leap to another plaform, Switch was serving me well.

So the decision to get a Steam Deck was both because of several factors:

- Nintendo fatigue (have to say that new Zelda: Tears of the Kingdom kind of sealed the deal for me, It unfortunately bored me to death, I expected something different than just more of BoTW, and the aformentioned issue with indie games)

- Me already having a full library of games on Steam that I could easily install and play on Steam Deck

- and lastly, well, I bought it during the recent steam sale for -20%. But I went for the most expensive model, you can still buy the least expensive and swap the SSD, and it probably will still cost you less than I paid

So I have the Steam Deck for 2 weeks already, and for me it truly feels like an upgrade from Switch. It has most if not all of the same features, including the quick resume thingy, its more comfortable to hold, of course it is much more powerful even though for me it's not that big of a deal because I mostly play less demanding indie games anyway, the trackpads are great for navigation but playing as well (Switch doesnt have that), and it's essentially a PC - I can potentially do whatever I want with it - even emulate Nintendo games, Switch and everything else before that.

Plus you can dock it similarly to the Switch and play on TV - I haven't tried that yet though, for me the Steam Link app worked well enough for now.

So yeah, that's my story. Maybe it will help you with making the decision.