To anyone who struggles to get all #Chrome based apps to work on #Linux with a #Arc GPU there is a bug in the Intel media engine that prevents these apps from working even without hardware acceleration. I only experienced it on my brothers machine without #Rebar while mine with it worked fine but there seem to be reports of people with a similar issue with it enabled too. Removing the packages related to that solves the issue and setting the Flatpak driver for VAAPI to dummy works too!
Only tested it on those two systems, both with a Arc B580 but I assume this extends to other arc cards at least from the Battlemage series and maybe even further in case the switch to the new XE drivers introduced it which is what I believe is going on. Also, for GTK 4 apps you have to disable hardware accelerated rendering because Vulkan rendering causes graphics glitches for some reason! Other than that and a few issues with Vulkan games my experience has been great for multiple months now tho