2022 and 2021 can coexist side by side. It even makes sense from time to time to have the two latest versions on your system. You can control this with a parameter in the CC Desktop app:


It's up to you to decide on how you want to get your programs updated. And you can go back one major version, if you updated and the update causes major problems with your current projects.
For some programs, I prefer manual updating, especially when I'm in the middle of a project.
You also need to know that the default application can be only ONE version and that uninstalling that version, you may have to manually assign the remaining version as default.
Also: older versions take up disk space, so if space is tight, you need to make a choice.