[blt]

Overleaf makes you pay for the history feature, and for more than one collaborator. Not good for long term collaborative papers.

[chongli]

They also let you clone a git repo of your project, so you can painlessly move out of Overleaf when you find yourself outgrowing it.

[_emacsomancer_]

Maybe. The deprecated V1 lets you. I'm not sure whether V2 will, at least without paying $12/month.