tbh I'd use configurable installer: download only these assets you'll be using
at worst case allow us to set up everything with full version installed and then cleanup
Sure. For the price of increased complexity, you can get something going (and in fact some games do do that, e.g. WoW), but to be clear, you're still downloading 55GB of assets. The game isn't actually any smaller, which is what OP was complaining about.
Also, this is why the big console makers are investing in cloud-consoles.
