4GB today is not that much. Current OpenBSD and NetBSD install recommend 2-3GB at minimum for a base OS and 10-16GB for a confortable usage (installing a bunch of pkgs/ports, swap partitions, and so on).
I'm not a huge fan of Overleaf, mind you, but I agree with those that say it does have its uses. The easy collaboration for people that don't like -- or don't get how -- to use git. I wish everyone I collaborate with liked git...