Apple didn't invent a "new form of discrimination", they have a product that works, and is tied to their ecosystem, nothing else. It is not even an exclusive technology, there are a hundred other messaging apps out there, and at least a handful of them are more popular than iMessage.
> Having a phone that doesn't open iMessage is basically a guarantee in the US that you will be excluded and ridiculed if you're a teen, and tbh even as an adult, not having iMessage can result in being excluded in the workplace as well as socially.
I can't speak about teens, but I haven't met a single adult in the US, so arrogant and petty, that they would exclude you from their social circle just because you don't own an iPhone.
And if you actually have encountered this, perhaps it is time for you to look for new friends.