[MereInterest]

Completely agreed, and this is why conflating protocols and programs is really obnoxious. This seems really common in proprietary software, where the conflation is deliberate, no protocol spec is defined, and the implication is that no other programs can interact with the protocol. (E.g. "zoommtg://" referring both to a software client and to a protocol.)

[Spivak]

This is what you get when OSs allow protocol handlers but not URL handlers. It would be totally fine if you could install Zoom and then zoom.us links would open Zoom but this is what we get on the desktop.