There should be an investigation regarding manipulation to the public for unnecessary upgrades. For example, I want to make a back up of my iPhone X, but my mac is asking me to upgrade the entire OS just to do that, why? I have Sierra and works great, I do not need to upgrade my system for something as trivial as a back up. It will affect the performance of my computer to worst installing crap I do not need and affecting other softwares.
The same with my iPhone 5. Yahoo needed for me to install new OS and other applications too, why? what processing I need to read a text message?
So all that is pushing you to upgrade to things you do not need. Then Apple comes and tell their share holders "everybody is running the new OS", but is not because people need it or loves it, is because Apple is making me, almost like black mailing me.