Having a backup at a cloud provider is fine, as long as there is at least one other backup that isn't with this provider.
Cloud provider seems to do a good job protecting against hardware failure, but can do poorly with arbitrary account bans, and sometimes have mishaps due to configuration problems.
Whereas a DIY backup solution is often more subject to hardware problems (disk failure, fire, flooding, theft, ...), but there's no risk of account problem.
A mix is fine to protect against different kind of issues.