It’s possible, but I doubt it. 99% of people use a personal computer with just a single user account on it (or they use a phone with no git client, so let’s just think about git users for now). With only one real user account on the machine they are not very likely to encounter this security measure.
Not exactly. Inside the docker container, the files you have bind–mounted will be owned by the same user who runs the git binary. You’ll never even notice the security check.
Today I'm sitting here staring at a 'fatal: unsafe repository warning' in my local workspace in docker and can tell you definitively that I have noticed.