For us several things have happened over time.
1. The immediate business need (new product development) for us was cancelled. So things that would have taken us further from a monolithic ruby backend, those went away.
2. We already have more than one auth / permissions system from merging with other business. I once saw that Ory might unite these systems, but what happened was we got bogged down in the relationships between these systems and what a unified permission model would look like. This in-turn made it feel like some refactoring would be necessary, beyond that of a naive permission check. This was generally undesirable by most parties.
Moving forward will be a combination of existing systems like auth0, and ruby monolith solutions like
Pundit. I was looking forward to ditching auth0 in our elixir systems. I may still but the earnest to do so is kind of gone for me now.