I’m having a good time even on an 11th gen mobile Intel processor with its iGPU. For more demanding games I use FSR to get much more bang for buck from the iGPU, on Linux it’s pretty easy to activate in almost any game. On a side note, Waydroid (with libhoudini) also has excellent performance on this setup.

The are ways to make almost all banking apps work on a rooted, even de-googled, phone. See here: https://lemmy.world/post/683341

Why not install SteamOS or plain Arch Linux on the GPD devices then?

There are good things to be said about the Ally, but I find the soon-to-be-released GPD handhelds more interesting. Both are officially stated to support SteamOS (which means plain Arch and possibly other distros should also work great) and offer something different from the Deck and Ally in that the GPD Win4 is much more compact, and the GPD Max 2 has a much larger display.