This is true in an idealist sense. Obviously storing all your files in a shady commercial cloud, with bad network and no local fallback, is a bad idea. But ther

This is true in an idealist sense. Obviously storing all your files in a shady commercial cloud, with bad network and no local fallback, is a bad idea. But there are potential alternatives: the server could be run by a trusted person in your local community, the files could be stored entirely locally (with synchronization running in the background), editors could handle upstream changes and show other users, conflict-resolution algorithms and editors could provide manual review for difficult conflicts (like Git but better support for non-text), etc. However, we don't live in an ideal world. Sometimes sending a file locally is good enough and everything else is unnecessary complexity. Some files will never be updated, some files are updated infrequently enough that manually synchronizing them isn't a burden. Storing files on the cloud also doesn't prevent security breaches, because someone can download the file locally; it does mitigate them, but using a secure (company or government owned) laptop is a strictly stronger mitigation. Adding collaboration support to editors is hard; Git synchronization (with manual push/pull) works well enough if you know how to use it, and Git has other purposes (e.g. commits annotate changes so they can be reviewed later, branches allow one user to experimental changes that don't affect their main branch); it's hard for me to imagine any non-negligible advantages of a collaborative editor over Git with experienced developers, and plenty of situations where it's much worse. One use case where collaboration provides a major advantage is brainstorming, hence tools like Google Docs, Figma, and Zoom's whiteboard.