> I've found that a good way to lower the hassle on starting a zoom is to create a permanently open meeting with your phone number as the meeting ID

But in zoom you do have a personal meeting ID, isn't what your describing just replacing that?

> My only complaint with zoom is the lack of a prompt before launching video.

As another commenter said, you can disable auto joining video and audio in the settings.

I do think it should be turned off by default though.