> You can definitely downgrade to an earlier MacOS. Sometimes you can, sometimes you can't. Going from Mavericks to Yosemite for example is one-way because i

> You can definitely downgrade to an earlier MacOS. Sometimes you can, sometimes you can't. Going from Mavericks to Yosemite for example is one-way because it includes a non-backwards-compatible firmware update. Going to Catalina is also one-way because it changes the file system from HFS to AFS. And iOS is famously non-downgradable.