You can run zoom in the browser. At least you could some years ago. Encryption is relevant depending on what you're doing but not everything needs to be super secret. A common practice is to email or use secure file shares while on the call to maintain that security.
You can also install and run Zoom in FlatPak which secures your computer by running the executable in BubbleWrap. If you know what you're doing, you can also sandbox it directly.
You can still. There's a small dark pattern to discourage it, though. You go to the URL for the call, click the button to launch the app, and when that fails, you see a small link to do the call in the Web browser.
When Zoom took the world by storm due to the pandemic, they're security was known to be horrible. They aquihired the key base team who are crypto experts and this presumably had some measure of positive effect.
Yeah, that line, "people say Zoom is secure", instantly reminded me of how they opened a port on localhost that any website could connect to to run admin shit on the system. So I wonder, who says it's secure?