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.
Those are all SaaS providers with meeting software available. If someone was using Jitsi, it was specifically to not use a login with any of those providers. They’re actively deciding not to continue operation with this. Its like when OnlyFans declares they wouldn’t allow adult content going forward
So… Tumblr?
OnlyFans announced it too, but walked back on it later.