Like the other guy said, used/refurbished pixels are pretty good deals. The overheating is a bit overblown, yes some people get a bad device but you can just return it if it’s really bad. My experience with the pixel 7/ 7 pro is that it’s very smooth and don’t notice any overheating even in hot climate, and Android 14 and also the upcoming 15 updates helps with heat and battery significantly.
Just to confirm, you’re using the full installation from here right? It works perfectly for me since a long time.
It’s on izzyondroid repo: https://apt.izzysoft.de/fdroid/index/apk/com.deniscerri.ytdl
Also I highly reccomend it, it even integrates sponsorblock so you can download only the parts without ads or intros.