You’re saying it like you found a loophole or something but it’s not a gotcha. Yes, if you manipulate sensitive data you shouldn’t use Google Docs or Photoshop online (I’m not imaginative enough to think of a case where you would put sensitive data in Photoshop online though, but if you do, don’t) or host your emails in the cloud. I’ve worked in a moderate size company where everything was self hosted and it’s never been an issue