Setting up your own git server is not hard, but it's not as easy as just getting github or gitlab to run it for you. Way too many people take the easier path, even though the harder path is not actually that hard.
There are also multiple solutions.
Bullshit. Getting it set up in a secure and public way is an order of magnitude or two more difficult than it would need to be for mass use which is what we're talking about here.
When you have a situation where a the vast majority of people find something too difficult, the problem (from the perspective of actually getting it happen) is not the people the problem is with the proposed solution.
> There are also multiple solutions
Multiple solutions does not generally make things easier/better even if it's desirable for other reasons.