Is your backup really a backup? A monthly test you can ask for

Backups fail quietly. A full disk, an expired licence or a changed password, and the nightly job stops without anyone noticing.
Once a month, ask your IT provider to restore one real file from last week’s backup and show it to you. It takes ten minutes.
Remember that Microsoft 365 keeps deleted items for a limited time only. If your email and files live there, they need their own backup too (sample advice).