Should I update to Big Sur or stay with Catalina

If you don't have an absolute NEED to upgrade your OS, don't do it. My rule of thumb is, if all the apps work just fine the way things are, don't fix what isn't broken. There are too many compatibility issues that could arise, causing you to have to spend a lot of time sorting them all out. And, if you rely on your computer and apps for your work (your source of income), downtime is something you don't need. 😉

I think you'll need a Mac user to answer this! The only thing I'd say (and this applies to all updates, whatever they are) is that you shouldn't do it whilst in the middle of a critical project. So whatever you do, try to do it tidily, as the Law of Conservation of Misery always applies...