I mean, Git LFS 'supports branches' in that the LFS content identifiers are checked into git as files and Git operated normally; LFS is just a way to replace those content identifiers with the actual content, and then vice-versa when you commit.
I think branching is the one thing that didn't get more complicated with LFS.
it's also tough when you have 1TB of data, over 1mm files and you might want to lock hundreds files in one go