A bit late, but let me add to the response. I had the exact same issue as you do, wanting to delete a file from all history/commits on Git.
You can actually do it and so get your space back. It’s just a bit of a painful process when you don’t know how to go about it, but it is doable.
I think for a small team where the project is indie, and you optimise your assets, Git is probably great especially if you are used to it, Perforce isn’t free unfortunately, but you can run it on your own AWS EC2 instance with a free tier that cost less tan $10 a month.