> Better question, why no use a more appropriate, instead of convenient, tool for the job?

Because ML engineers also want version control and easy history and rollbacks and pull requests with code reviews for model changes.

There is no tool that does that except for the version control systems that programmers use. Other disciplines doesn't seem to care as much about these things.

Edit: And in general the extra storage/compute cost of storing it there is less than the saved work in programmer hours from having version control. It is much less worth adding support for larger files than trying to build an entire separate version control solution. Google already has support for images in the version control system, with image diffs etc, there is no reason not to also add support for these large ML models similarly.