Just checked, my C drive has a bit more than 1 million files. What are you doing that you have 5 million separate files in your Google Drive?
Geospatial artifacts can be very large, and also can be spread across thousands and thousands of files (20+ zoom levels on Earth, with enough 256x256 tiles to cover the planet at each zoom level, for example).
Just because your workflow doesn't involve lots of tiny files doesn't mean other people's don't.
Besides, most of those commenting in the issue are talking about their organization having hit the limit, not individuals.
That may be what you use it for, but that doesn't mean other people use it in that way. And it doesn't mean that's how Google represents it in their documents.
I tried to look for documentation about what Google Drive should and shouldn't be used for.
In the FAQ Google Drive said it could be used for storing any file type. There are instructions for how to backup/sync any folder on your computer to Google Drive. If you're an organization that has several people backing up folders with large numbers of files, there's nothing Google says that makes you think you shouldnt use it that way.
https://support.google.com/drive/answer/10838124?hl=en
The only thing that indicated what it shouldn't be used for was content policy page. It basically says it shouldn't be used for illegal activity and that it shouldn't be used for streaming video.
Its SLA.
Or more precisely, its lack of one.
It seems odd that someone would say that you shouldn't use Google Workspaces for work.
See some comments on the tracker, some orgs have a multi sites set up across an entire nation. I wouldn't be surprised if 10k+ volunteers at some NGOs are on that sort of plan and use it as their personal storage solution on top of all the things they sync for document counts heavy work.