Comment by dspillett
Contacts and such I currently "trust" the default behaviours for, though I've got some noted down the old fashioned way for emergencies or if I somehow get looked out of the account. I keep meaning to use Takeout as an extra measure. Photos I sync to my own backup system via rsync+SSH via Termux. Everything else is easy enough to replace or came from other sources (my local media library, etc) anyway. I used to backup more (podcasts & such) via rsync but recent versions of Android have made that more difficult without rooting.
For backing up Android contacts, go to https://contacts.google.com/ on your phone or laptop. You can export everything as csv.
Takes less than a minute It's well worth doing from time to time.