While Jitsi is open-source, most people use the platform they provide, meet.jit.si, for immediate conference calls. They have now introduced a “Know Your Customer” policy and require at least one of the attendees to log in with a Facebook, Github (Microsoft), or Google account.
One option to avoid this is to self-host, but then you’ll be identifiable via your domain and have to maintain a server.
As a true alternative to Jitsi, there’s jami.net. It is a decentralized conference app, free open-source, and account creation is optional. It’s available for all major platforms (Mac, Windows, Linux, iOS, Android), including on F-Droid.
How disappointing.
It was great for sharing private contact info with Google/Facebook/etc friends without revealing it to those invasive services. Instead of sharing your private address where it would be harvested, you could meet in an anonymous Jitsi room, exchange addresses there, and contact each other directly from then on.
Self-hosting doesn’t solve that use case, unless perhaps you’re willing to buy throw-away domains and IP addresses every time you do it.