If you value it, back it up. The built-in "backup" in M365 is aimed at covering their arse, not yours. We use Cove (Solarwinds as was). Sensibly priced, automatic, effective.

It depends what you mean by 'Automation'. We use a backup product that does all the usual stuff (incremental backup to the cloud on a schedule, holds local copies, encryption blah blah etc. etc.). If you know what you are doing you can build yourself a recovery appliance…

The backup functionality built into Microsoft365 is all to do with Microsoft losing their systems.  If you want to recover something YOU have accidentally deleted, or any of the more advanced backup functionality (e.g. the ability to recover a single mailbox from a date in…