There is a huge gab between high and low and devices. Some manufacturers will want to sell - and many consumers will buy- a few models that are more expensive than $150 but less than $1000.
There’s perhaps a gap in the $150-$400 range, but used phones can definitely be found there, and I would bet that there are Android manufacturers that sell new phones there.
(All prices are USA and before tax, so other markets will be a bit more expensive.)
Below $150 you only have the cheapest models by brands like Xiaomi, and over $1000 you only have the flagships.
There are plenty of models in the middle, not only Pixels but also a plethora of offerings from Oppo, Samsung, Xiaomi, Vivo, Honor, Poco, etc. Name any [X,X+100] interval in that range and there are phones of that price. Last week I went with my mother to buy one for her, she settled for the Oppo Reno 8 (about $500) but there was the Lite version at about $100 less, the Pro version at about $100 more, and then other lineups from the same brand (Find X5 in Lite/normal/Pro versions, etc., and many, many others we didn't even look at); and that's within a single brand.
So your parent comment doesn't make much sense to me even if it's hyperbolic. Maybe the available offer is really different in the US, here there are definitely plenty of models of all prices. A different story is that all brands tend to make the same decisions and follow trends (e.g. ditch the headphone jack, make screens larger, etc.) so everything is sameish and even if there are hundreds of models to choose from, it's possible to not find a model that fits one's needs. I myself imported my phone (Pixel 6 Pro) from Australia because no brands other than Apple or Samsung seem to sell 512 GB storage models here...
But even if SMS costs money, why not just use free apps like Whatsapp or Signal?
And if SMS does cost money for the recipient, does that mean it doesn't get used for 2FA? I imagine some people would block it in order to prevent unexpected costs.
I had not expected either of those, but I'd imagine if iMessage costs money on Android, that would massively increase the popularity of either Whatsapp or Signal.