Hello,
I worked for 3 weeks just fine with PS, AI and InDesign (all CC 2021) and then one evening the applications won't open again. They are freezing when starting up or crashing right after the start. I have changed nothing on my system, have installed no new software or anything I could imagine causing this behavior. Looking for help I browsed the internet and found that for many people only reinstalling the CC2020 applications helped. So I did that because I had work to finish. I think Adobe is not doing enough to help those many designers who report the exact same weird behavior of their CC 2021 suites.