I get your point, but where I don’t agree is that sideloading is more insecure than already exploited systems. What safety does disabling sideloading provide when the same user vulnerable users are able to be socially engineered to bypass several restrictions and install the test flight app or a management profile to give hackers control?

It’s not as if sideloading is going to be allow users to click a malicious ad that pops in at the last second where the real download button should be. It is going to behind the same multiple step processes that the current test flight or MDM vectors are