Large binary assets don't scale in git, even with LFS and similar solutions. At that point the pain of having code in multiple places far outweighs the pain of being on a really annoying platform like perforce. As you mentioned you'll also miss out on a lot of tooling (in perforce and unreal) and trying to replicate that functionality with git on the backend (struggling with large binary assets) will bury the project.
If you're making a game perforce is the only legitimate option. Unless you hate your developers, then try alienbrain.