It's not hard, but it's advisable to eventually set up a parallel blank Arch install where you configure everything from scratch based on things you liked from Omarchy.

I think the beauty of this is to get to understand all components in your system, which is quite simple actually.

You're not supposed to with these macOS-like distributions, that's their whole idea, "take it or leave it".

Don't. Just use arch if you plan on changing. It's not for you