My recent experience is no – the first backup went just fine, but all subsequent attempts to add to it have failed, giving various errors in the logs, including mounting problems, timeout during the initial write test, bad database, etc. I did rename the drive between backups, maybe that was bad? The log shows Time Machine using the new name and finding the drive just fine.
Googling this I see that people have these same problems with external hard drives, though, so I’m wondering if anyone has been successful using a thumb drive and if there’s any trick to it.
Or traveling in time. Just imagine if you forget it in a computer during a time jump. Not only are you stuck but some sod gets zapped across time for using a library computer. When all they wanted was to find out if they had gotten an e card for their birthday.