But the average user is not writing automated systems to populate google drive with millions of files. Once you are doing something that unusual you should understand that nuance. Sure it is fun to hack a tool designed for one purpose to serve another, but if you are writing code for use in production you have to understand these types of design differences.

Drive is very closely linked with Docs, Sheets, Slides. These aren't "files" in the traditional sense. These, plus things like PDFs, videos, etc are what Drive is designed to help manage.

If you have 100,000 source code files, art assets or something like that, you probably don't want to use Drive to manage them. The UI just isn't built for it and it doesn't scale.

I'm pretty sure Google Drive Desktop software by Google doesn't restrict the syncing to these basic for formats.

I certainly joined GDrive believing it is designed as a cloud drive where I put whatever I'd like.

The browser interface doesn't scale. But the mount as filesystem absolutely scales enough to accumulate 5 million files.