Instead of the battery dying and you throwing your phone away, it just happened that the battery died, and you searched for a compatible one, that either didn't exist or cost 70% of the price of a new phone, so you threw your phone away.
Now, if you want to talk about standard battery sizes, I'm listening.
As someone who frequently changed their phone batteries and bought spares you are talking out your whole ass about their lack of availability and price, you just made up some shit then justified your argument with your made up shit.
It was extremely useful when it was more common than non-replaceable batteries. Most of the time, you could find a better battery than the stock one at a cheaper price.