[vsareto]

It wouldn't be unreasonable to say database products are an order of magnitude or two more reliable than code written by many teams.

There's some advantage in having code separation first, but it is admittedly not a benefit of reliability.

These half-measures are generally done when converting an older architecture to a newer one. I don't think many places actually do big bang conversions/releases going from monolith -> microservices where you can do everything correctly. That runs counter to the CI/CD trends that we taught them.

The other issue might be a conflict in database table constraints (or worse, triggers/sprocs) that don't match your microservice boundaries, so the business ends up wanting wins faster than your team can resolve those conflicts.