I have been considering selling my 3060 ti and buying a 6700 xt for a while now. The main reasons are (potentially) switching to wayland, +4 gb of vram, hardware acceleration in firefox (and steam too, it's leaking vram for me with nvidia), potentially vr on linux with my quest 2 (a lot of things in alvr seem to be locked for nvidia) and better compatibility with linux in general. I don't really care for productivity or rtx and dlss (it's not like they work in most games anyway). The upgrade would cost me at most $75.
I don't consider this an upgrade, it's more of a switch. The 6700 xt new is almost the same price I can sell the 3060 ti for. I won't be upgrading for at least 5 years.
If you ever plan on using a GPU as more than a toy for running games, then stick with Nvidia, though tbf there's not a whole lot you could do with 8GB.