Why not savannah instead of Gitlab?

I’m trying to learn how to use Git, and reading on the forum I found that Github is not a good idea to host my projects.

I then encounter that Trisquel uses Gitlab’s community version, having the user registration disabled because it uses google’s recatcha.

Is there a reason Gitlab was chosen over savannah? Is it a good idea for me to use savannah page to share my future projects?

I’m guessing that using Gitlab means that trisquel developers could host their own code repository, and savannah code web hosting must be finite and would allow very big projects. How is savannah financially supported?

Thank you.