I've never ended up with undesired software on my system except for under two circumstances: either (a) it's installed by the OS vendor, or (b) some proprietary indie software I used got bought by a shady company who now wants to spy on me and sell my data. Systems like Gatekeeper don't protect against either.
> Also, it’s just such a bad security precedent. This page describes the error you get as “the typical macOS Gatekeeper warning”, as though it were just another piece of corporate silliness, like clicking through a EULA.
It mostly is another piece of corporate silliness. For most people it rarely does something useful. But I agree; if you're courting normie users you should just pony up and get your code signed and notarized. Otherwise just tell people that if they don't already know what Gatekeeper is and understand the risks of bypassing it as well as how to do so, your software isn't for them.