Plenty of high-end monitors need more bandwidth than DisplayPort 1.4a can provide if operating uncompressed, but models with a DP 2.x port typically cost a lot more because it needs reasonably expensive hardware to make it work. That means that if you use DP, then you have to compromise between spending more money or using Display Stream Compression. Monitors needing that much bandwidth basically always have an HDMI 2.1 port that can handle it uncompressed, but without this patch, if you used HDMI under Linux with a Radeon GPU, it wouldn't run in HDMI 2.1 mode, so would give even less bandwidth than DisplayPort 1.4a, and you'd experience even more compression artefacts, despite the same configuration working perfectly under Windows.