Apple added that allowing sideloading would potentially force users to accept privacy and security risks, because some apps necessary for work, school, or other tasks may no longer be available on the App Store, and scammers could also trick users into thinking they are safely downloading apps from the App Store when that is not the case.
And yet, every day, millions of Mac users make it work.
This is such a flawed argument, I hope they were embarrassed drafting it. They want their money, full stop.