What is more complicated than spotting the developer name in small letters in the App Store, open a new app, safari, goto Google, input the developer or apps name, click a link to go to the site so on and so forth … There is a fare amount of over simplification in your steps … don’t understand the point of it.
Finally It just depends how you do it. Sometimes you just search on google, click a link to the App Store, download, create the account and subscribe in app. Other times you do it on devs site and than move to the app (its actually more steps). On the other hand you are forgetting the cases where you buy more content or upgrade … quite often it is done in app or at least is initiated there.
But I agree with you. So many millions spent in lawyers, tax payers money in judges, regulators, suing governments … for something that looks so trivial
Cheers.