Isn't that the beauty of self hosting? How could anything be enforced on user-controlled servers? Practically everything self-hosted is open source and how would enforcing anything would even work?
New laws comes to mind. If a government decides to try to outlaw encryption again, cloud/hosting companies located there wouldn't have a choice but to comply, or give up on the business. The laws could also be made in such way that individuals are responsible for avoiding it, even self-hosters, and if people are using it anyways, be legally held responsible for the potential harms of it.
You are right though, it gives significantly more control to users. It's just realising 100% of the benefits that might be trickier.