An easy solution that does not require any usernames or passwords can lower the barrier of meeting people online. Privately. There are many commercially successful video conferencing platforms but in many articles you can find online the open alternative is not even mentioned. So I chose to not mention the others here. Just open alternatives. And when I say open, it means anyone is free to run an instance as part of their infrastructure or even use any of the available publicly-running instances.
The room is where people meet. They can also communicate voice-only (Settings → Manage video quality). No need for any special software. The technology used behind the scenes is WebRTC, an open technology developed mainly by Google and optimally supported in many browsers (Chrome, Firefox, Safari, Electron) and suboptimally (I have never tried) even in Opera and Edge. Privacy is guaranteed. No ads, no trackers and the option to run your own instance (which does not have to be public at all). When only two participants connect, the server just helps them to establish a peer-to-peer connection where all the data travel straight from one participants' computer to the other.
https://meet.anyone.eu.org/ List of other public instances can be found at: https://github.com/jitsi/jitsi-meet/wiki/Jitsi-Meet-Instances There is at least one other similar project, also open source, also WebRTC, but all the other details done differently. Have a look: https://letsmeet.no/ and its source code is available at https://github.com/havfo/multiparty-meeting