After a bit of a scare a few weeks ago, I've started doing regular Google Takeout data downloads of email in addition to my normal backup procedures. I also verify that I can load the resulting mbox files into Thunderbird or another client.
I don't use Google Photos, I have my own local storage, backed up in triplicate by three different processes.
Finally, I'm a heavy user of Google Drive, but that is synced locally on several machines, and backed up in triplicate using the same processes as the photos.
Never rely solely on a 3rd party for your critical data. Always have an exit plan. And test it regularly.
I don't use Google Photos, I have my own local storage, backed up in triplicate by three different processes.
Finally, I'm a heavy user of Google Drive, but that is synced locally on several machines, and backed up in triplicate using the same processes as the photos.
Never rely solely on a 3rd party for your critical data. Always have an exit plan. And test it regularly.