I partly agree with you, however it's possible for devices to have limited access to the internet, or even no direct access but still be accessible to devices that are on the internet.

If I have a smart device at home I may put it on a network that has no outgoing access to the internet, but it would still be nice to be able to connect to it with a web browser without getting angry expired certificate warnings.

It's not the worst problem to have, and I don't think it's easy to fix, but it's still annoying.

Is there a certbot client for ESXi?