Two things:
(1)
Old versions of Zoom require manual deletion of files and folders from numerous places, while newer versions allow you to choose File > Uninstall Zoom. But even following Zoom’s instructions leaves cruft in macOS: on my Mac it left behind an invisible .zoomus folder, an install.log, and a ZoomChat.plist.
I was alerted to these after they got deleted by using the following downloadable Terminal script:
and following the simple instructions in the ReadMe.
(2)
Zoom purposefully hides the functionality to join a Zoom call via a web browser by first requesting you to download their software. (After downloading it will give you a link to join via your browser, which launches the app).
There are open source browser extensions for Chrome, Firefox, and Edge (Operas version coming soon) that make visible that chat hidden link without having to download the software first.
You can see the source of the project and links to the extensions here: