Do you think anyone would have installed Zoom if they knew that it would allow any random website to activate your camera?
The question I see is really that Apple doesn't inform its users of the existence of this feature, unless you really search for it. Having something as simple as a functional-equivalent to Windows Defender with its own icon in Control Panel, which is fully enabled in the default operating system installation, should be sufficient.
Personally, unless I am specifically aware of the existence and enabled status of some anti-malware application, I don't think it's a good precedent to set for operating system vendors to start silently removing software from peoples' machines. Really all it should take is apple making people aware of the feature's existence.
For a bunch of my family members, even simple errors mean almost nothing to them. They'll stop what they're doing and wait for help even on an error that (it seems to me) they could have simply read and addressed themselves. They've never examined the system tray, and dismiss any popups that come from it. Making them aware of systems like this only serves to confuse, because they don't really understand the problem it's addressing in the first place.
Machines for power users aren't going away. There are more operating systems than you can shake a stick at, and the number keeps growing. But for a lot of users information can be paralysing, and I wonder if having a strongly managed and simplified system akin to a phone isn't a better idea.
Yes, I'm quite confident that millions of "normal users" would still have installed Zoom knowing that.