They did buy zoom.com from someone in 2019, though, for $2M.

https://domainnamewire.com/2019/03/23/did-zoom-pay-2-million...

Interesting. I used to buy Zoom modems in the 80s-90s (https://en.wikipedia.org/wiki/Zoom_Telephonics), but apparently they have nothing to do with either of the other two Zoom companies mentioned here. I had occasionally wondered but never looked into it until now.