Private Endpoints allow establishing connectivity, which occurs exclusively over the backbone Azure networks, without the requests ever emerging to the public Internet.
The approach bridges the gap between Terraform and other tooling that is not available via some custom provider. It can be used instead of implementing some custom provider, which allows to stay in the technology stack already adopted by the team. The approach plays nicely in the cases, which the concepts provisioning, deprovisioning and drift mitigation could be applied to. There are some things that one needs to know when using it, but in general some new case can be implemented with the pattern only once, and as long there is no need to change it drastically, it will continue to live (it is even resilient to external impact – which is covered by the drift mitigation).
Upd. March 2022: I've been banned at the Oracle Cloud for having Belarus as the origin country. All attempts to restore the access were rejected with no explanation. Still, I hold this article as a nice exercise, although now I have to warn readers of possible consequences of using Oracle Cloud.