Linux doesn't routinely create "restore points' because Linux is thankfully not cursed with the Windows registry or equivalent. There has been no general need (as opposed to occasional individual choices) for "restore points" or their equivalent. If an upgrade breaks something, in most cases, it is usually fairly easy to fix it with a text editor and an internet connection (to get any desired files).
I found a link that explains a procedure for downgrading a Mint version, but it is not necessarily a simple process. I can't recommend it and have no way of testing it.
If you try it, be sure to back up any crucial files to external media
first, in case it fails.