Unfortunate, DSC works fine on apple silicon. I did notice displayport-related regressions on my old 2015 mac way before big sur though, Apple's track record is not great.
Yea, the Apple Engineering Department asked me to run a ton of diagnostics, both on Catalina and Ventura, then came back with “Would you ask Dell to confirm their monitor is compatible with MacOS Ventura specifically”. Lol