What happens if your house burns down with the drive in it? That’s the main point, you either need a drive off-site or you need cloud storage, which is off-site.
Net access is getting fast enough now that it makes sense to keep frequently accessed data on the cloud. As someone who is running an online radio station, I have several systems that are generating small but important files. I need those files to meet license reporting requirements and can’t lose them. Having them immediately auto backup to the cloud is vital. As well, if I somehow get hit with ransomware and my files get encrypted, OneDrive lets me jump back to just before it happened and recover most of my data and file library.
Both of the above entities could have recovered within hours if they had a proper cloud recovery setup.