Are you using KDE? I'm on a fresh install of Arch with KDE Plasma on my gaming computer and I agree, it's janky as fuck. I've gone through everything I can find about how to deal with the flicker, but it's still there and it's an awful experience.

I have none of these issues on my Arch laptop with Gnome, so I'm going to switch my desktop to Gnome too when I have the time. Plasma is not ready for mainstream use if this is the best that it gets. Gnome however is awesome!

So, I suggest changing your DE to Gnome. If that doesn't fix the problem then switch to Pop!_OS. It's a completely plug and play distro and I never had a single problem with it. I only switched to Arch because I wanted to get HDR support which requires Plasma. Well, it's not worth it. I can't even use adaptive sync which is a pretty big deal for gaming.

Good luck, we're all counting on you.

Edit: otherwise Arch is an awesome distro. The power you have with all of the available programs is great! So, now it's just about getting the screen rendering to be stable.

This may seem odd, but check if your mobo has a bios update. Often bios break uefi standards to appease Microsofts non-standard requirements.

These get fixed overtime as ACPI bugs are fixed.

I switched to Linux Mint a few weeks ago and I'm not having any problems with games. Everything in my Steam library plays fine.

For a long time I couldn't get a stable distro working on my HP laptop with Intel 4 core & Nvidia 1660ti but after numerous successful daily driving on my desktops + steam deck of course I tried Bazzite which did the trick. Everything runs smoother & I haven't encountered anything unable to run because the steam proton is mature. Lutris is perfect for anything to do with alternative launchers, roms, I even got modded black ops 2 working and I never thought that would be possible.

I wish you the best of luck.