I used bazzite and I ran into the exact issues you described above. It worked, and it worked well, but anything extra that I wanted to do required jumping through a shit load of hoops and bouncing around between bazzite forums, fedora forums, and universal blue forums to maybe not even arrive at a reliable work around.
It was extremely valuable because I had to learn a lot, but it just wasn’t nearly as seamless as cachy.
Bazzite will play steam games right off the rip and it will do it well, and is an easy install. Beyond that it can get harry if you’re not just using flatpacks.
A lot of people will say “just use distrobox” if your solution to make something work in this OS is to download and use another OS, why wouldn’t I just start there with the other OS?
To be frank, I haven’t used paru. I’m relatively new to arch but I’ve had nothing but good experiences with yay