John Gordon writes about losing images in an old document on Google Drive:
I encountered this issue right when the transition was made from the old editor to the new editor, which might have been around 2010 (not sure about that). Since then, I had gotten weary. Whenever I'd create an important document, I'd create a folder on Google Drive, put the images and other assets in there, then include them in the document. In other words, they would never be just in that document.
With Google Drive, I first thought that all files (Goole Docs, Sheets, etc.) would be synced locally, and that my local backup solution (Time Machine) would save a copy. But to make sure that happened, I tried to figure it out and create a matrix of what was viewable and editable offline: 2013-09-28 Criticism of Google Drive. In the end, I figured it was very hard to get a reliable backup of Google Docs, Sheets etc.
Back then, I hated the Microsoft Office format lock-in. Google seemed somewhat more open, and it was. But only in the sense that they had an export to the Open Office format. Their own format is very much closed, and has remained so for all this time. With Microsoft Office at least your local backup solution works fine, and the format is understood to a certain degree and imported by a number of software packages, some of them open source.