I would never trust Google for anything critical for that reason. Google Drive is just another backup for my photos.

I know, I use Takeout on a regular basis, backup phone photos and such to a NAS, and my primary Gmail is a custom domain (I've started paying) that I could switch to another email provider if needed.

Also see Google+ failing to accomplish much of anything positive in part by insisting on True Names like Facebook which it was trying to kill, and shutting down some accounts that failed to do this to their satisfaction.

For extra credit, the leader of the Google+ effort didn't use his True Name.

To extend this to the theme of the topic, while Google obviously displaced a lot of incumbents starting with the AltaVista search engine, do we expect this to happen in the future?