I don't know how freedom of choice will come in the same operating system but different hardware?
Then why would you go from M2 MBA to M1 iMac?
If I were you and I didn't want a laptop anymore then I would get a current iMac or an m4 Mac mini.
As far as App Store restrictions they would be the same pretty much with most Mac's. Get an iPhone or iPad if app restrictions are an issue on a Mac.
Maybe just keep what you have and figure out why there are restrictions, what can you do about them and then go from there?