Hell, there was (and still is I think) even all the ridiculous rules around "can't link to a website payment outside of your app" and "definitely can't tell the user it's cheaper not to buy it thru the app where Apple takes a 30% cut"
I distrust Microsoft and Google as much as I distrust Apple, but damn do people give Apple so many passes "yeah well they use that 30% cut to pay for all the security and services they offer!111" you really believe that? How come so many 0-days & other exploits are found by GOOGLE'S project zero? Does Apple not pay enough for their own research into that stuff?