That's part of it, yes. Also the fact that existing software was apparently built with the assumption that you always want to receive calls, that they are important, so important they can't be disabled or ignored.

More fundamentally, I have a problem with interrupting synchronous communication, and especially the cultural acceptance of it. As I noted in my original comment.

>> the expectation you can immediately and synchronously interrupt any person and demand their full attention

> Needs to end as soon as possible.

What can you do if you don't want to block unknown numbers, e.g. you get a call from a hospital about your injured relative, but you have blocked all unknown numbers