"Apple warned that alternative app marketplaces and payment systems could increase risks such as malware, fraud, scams and privacy threats"
It could also decrease risks of malware, fraud, scams and privacy threats if developers share source code for public review and users compile apps themselves
It's difficult for those risks to evade detection when the public, i.e., those who actually care about these risks, can read the source code before compiling, installing and running the software
There have been many open source attacks in the wild. Not saying it's a bad idea, it could reduce bad actors, but you're still relying on maintainers to review or even trust a regular user to read before using
"Apple warned that alternative app marketplaces and payment systems could increase risks such as malware, fraud, scams and privacy threats"
It could also decrease risks of malware, fraud, scams and privacy threats if developers share source code for public review and users compile apps themselves
It's difficult for those risks to evade detection when the public, i.e., those who actually care about these risks, can read the source code before compiling, installing and running the software
There have been many open source attacks in the wild. Not saying it's a bad idea, it could reduce bad actors, but you're still relying on maintainers to review or even trust a regular user to read before using
Doesn't make sense to prohibit the possibility that someone else can do as good or better job than Apple
That prohibition only makes sense for Apple
Prevent competition, limit options available to users, remove user choice
Good luck the only thing you’ll have is scam App Stores and malware.