The question is more like where else would you put your backups?
If you care that much about the data then yeah you’ll probably take the time to export that snapshot to a third-party service, possibly another cloud. But if you’re just going to throw it in an S3 bucket or something, you’re basically just manually doing what AWS already does for you internally, so a complete waste of time.
Eh, it’s not a complete waste of time - AWS will only allow for 35 days of snapshots because they want you to use yet more managed services like Backup. Tossing even 60 days of backups on S3 can make clients a lot happier.
The question is more like where else would you put your backups?
No, it is not.
Depends on the criticality of data. If you have truly business ending or catastrophic business results from days loss, you should be using off site as well (Amazon will also do it for you) and possibly a secondary off site not with Amazon.
For smaller less important shit you probably can’t afford to do all that.
It’s not free of risk (regional datacenter outage, account termination), but for a lot of companies the above are acceptable risks compared to the cost of managing this yourself.