I've had my Google account for well over a decade and have accumulated a lot of emails, photos, etc. The risk that Google will lose my data is extremely small, but it's not unimaginable that I might accidentally delete data, or that I get locked out my account. Therefore, I periodically back up my account. Google provides https://takeout.google.com as a convenient way to do so. Here's how in more detail:
Incremental backup
As it turns out gmail and photos use most space, so it's worthwhile to do an incremental backup on these items and simply do a full backup on everything else.
- gmail
- empty trash
- in gmail's search bar, type "after:2021/01/01" (adjust the date)
- hit the selection checkbox to select all mails
- hit the "Select all conversations that match this search" link
- hit the "label" button and select "Create new label"
- select a descriptive string, e.g. "backup-20210101-20210307"; this label will be used later
- photos:
- create an album for all photos since the last backup, e.g. "Backup 2021-01-01 to 2021-03-07"
- tag all photos in the timeline after the last backup with this album; this album will be used later
- create an export in https://takeout.google.com
- select the backup label for mail
- select the just created backup mail label for Mail
- select the just created backup album for Photos
- select all files in Drive but uncheck the photos (if that corresponds to Google Photos
- choose Drive as the destination of the takout archive; zip files greater than 2Gb work fine
- wait for takeout to complete
- copy the takeout zipfiles from Drive to another medium, e.g. an external drive
- delete the takeout zipfiles in Drive
- schedule the next backup in Google Calendar as a reminder
