“Take the “BatteryGate” for example. Apple secretly and deliberately reduces the performance of old phones in order to boost new phone sales in the name of extending the battery life. The company only revealed this after being caught red-handed.”
If they wanted to encourage people to buy new phones wouldn't it just be easier to not support older phones with new iOS updates? Why base the slow down on battery life instead of just slowing the phone down after two years?
There are much easier ways to encourage people to buy new phones if they wanted to be underhanded than the Rube Goldberg conspiracy that you are suggesting.
You and me know to not use something like this for any kind of sensitive site. But the common iOS user doesn’t know this. Apple is protecting their users and their platform.
It’s 2018. making a web browser where all traffic goes through the browser makers server, being unencrypted and then reencrypted is not acceptable any more (I would argue it never was, but then, back in the days of 9600 bits/s it was more excusable)