5 seconds of research yields this: https://jitsi.org/built-on-jitsi/#partners
What's the point for them to put all the money in?
Will try dig up some posts...
EDIT: Looks like one person self-hosted an instance on a Hetzner cloud instance for 2,49€ a month. https://dev.to/noandrea/self-hosted-jitsi-server-with-authen...
Regarding the official Jitsi meet site: "On a plain Xeon server (like this one) that you can rent for about a hundred dollars, for about 20% CPU you will be able to run 1000+ video streams using an average of 550 Mbps!"
https://jitsi.org/jitsi-videobridge-performance-evaluation/
I'm not a backend guy so not sure if this takes everything into account.