The last Android phone that I had was a Galaxy Note 4. Along with the bloatware that Samsung pushes and can not be uninstalled, there was an app called Peel Remote. This app is also published to Google Play Store and updated from there.
So, after updating my apps from Play store to latest version, as you are supposed to do, at morning I woke up and saw my home screen was changed and showing an ad. Also, I realized, sometimes a full screen ad pops up, randomly when I was using the phone. After a lot of investigation, I found out the uninstallable app that is included in the phone, Peel "Smart" Remote (the irony), which is published and updated through Play store, silently decided that showing full screen ads and replacing my home screen with ads was a good move, through an update.
There is NO WAY that an update like this could be pushed to Apple's App Store.
I am not sure how or when it has improved but my trust was breached and it was not restored still today. There are a lot of junk/fearmongering/placebo applications in Play Store, e.g. "RAM Cleaner" or random "Anti Virus" applications.
Apple should relax their requirements, sure, but I am really willing to stick to the Apple store to prevent stuff like this.
I understand this clause is there to protect customers from shady apps that try to trick customers to pay for non relevant things (e.g. app asking people to purchase something else to activate the app outside of app store), while it is too convenient for Apple to guarantee that they will get their cut.
I think that Android provides the best of both worlds: gatekeeping on the official app store, and the option (with warnings) to install from other sources. I believe that families and enterprises can also disable third-party installs.