You need an Apple ID for the Mac’s App Store, but the Mac’s App Store is very much the second banana on MacOS. You can open up Chrome or Firefox and download an installer for any ‘ol app, or another app marketplace entirely.
That said, if a developer hasn’t registered as a “Trusted developer” with Apple, installing an app will ask the user if they’re sure that they want to install the program. All of the settings around trusting known developers are at the OS account level. They require a local admin login, not an Apple ID. Its somewhat similar to what Google does with Android.