Is there solid documentation or tutorial on deploying hydra + kratos? That's what stopped me last year. I've found some subtle pointers in some buried github issues, but nothing definitive. Which surprised me because one would thought that's the main use-case for many people and should be documented well.
I guess with Zitadel they don't paywall any features, and with self-hosted option you get essentially the same thing as with hosted. I think you can probably even do multi-instance, however maybe without a management interface for that part of it... When I read Ory language, it says to me "you can try it out locally and itegrate, but we want you in our hosted solution right after" (I could be wrong, I was just glancing casually...)
https://www.ory.sh