Most applications are/can be compiled for arm. You just need the right repo or to compile from source.
Raspberry pi’s are very popular and are arm based already.
You don’t need a translation layer unless the software is proprietary and the vendor isn’t willing to compile for arm.
Have you looked? Almost all software on flathub (definitely the majority) lists aarch64 (ARM). So yes, most things work.
Again, proprietary software is the main issue here. Open source software is pretty easy to recompile.
I understand qemu can emulate x86 in those cases, with a performance hit.