What distro to choose in parallel to steamos

Hello community!

I come to you for advice. Using an m1 macbook air since 2020, I installed popos on my old 2013 macbook pro and I was quite happy with it but... I bought a steamdeck two weeks ago and exploring its desktop mode made me reconsider some choices. Using distros based on different systems, with different commands, desktop environment, etc. gets a little confusing for someone like me, who doesn't use linux as my main machine. Do you have any advice for me? From what I understand, steamos is debian-based while popos is ubuntu-based: is that the biggest part of how a distribution works, ie commands, etc.? Good ui/ux is important for me so i should maybe use nitrux or deepin, that are debian-based, or is it a bad idea to choose a less common distro for a amateur like me?

Thanks in advance, I'm a bit lost.