Jitsi Meet [0] is the simplest video conferencing solution that I have ever come across. To use it you go the website (or the mobile app) and that's it.

You have a free, private, end-to-end encrypted, efficient, multi-participant video chat which allows screen sharing and shared document editing. It works on every modern browser, you don't need to create an account, and you don't need to install an app (except maybe on mobile OS's). It's open-source and you can run your own server.

[0]: https://meet.jit.si/