Agreed! This week I used Jitsi Meet (not the self-hosted version, but I like that I can set that up if need-be) to do just that; contact technologically illiterate family members without me or them needing to have a certain OS (on smartphone, tablet, or personal computer) and set up some app.

Just a modern browser on a device with a camera and microphone. This is how this type of software should work.

It passed the grandma test.