I am trying to make use of a RP4/8Gb as a desktop machine. Manjaro was the first distribution that worked out of the box on it (and I tried several others incl Ubuntu before that). The thing is that currently the performance of the Pi is so bad that it is not very usable as a desktop, especially the graphics performance. In hope to fix it I moved to Manjaro unstable with XFCE, installed the 5.10 kernel, configured the Pi to use the KMS driver and overclocked not only the CPU but also the V3D. Yet the MotionMark benchmark continues to show poor performance (score of 1.08, on the Firefox browser, with acceleration enabled and on full screen 1080p@60Hz).
I wrote in the Raspberry Pi forum and I understood that the Raspberry Pi OS ships quite a bit of optimised code in various places. This includes for example the Chromium browser that arguably runs faster there than in Manjaro (MotionMark above 30).
So my question is - is the Manjaro distribution for ARM shipping any optimized software for the Pi and if not - why? Any advise on how to optimize Pi’s performance will be welcome. Thanks in advance.