Why not just use Google Drive to back up your "essential" data, after encrypting it? All of these models people here are coming up with eventually secure again

Why not just use Google Drive to back up your "essential" data, after encrypting it? All of these models people here are coming up with eventually secure against your adversary once they obtain your encrypted data, so why not just start there? Feels like people are just playing into some kind of fantasy, rather than trying to come up with workable and practical security measures...