the phone companies would be able to charge peak megabyte hours to specific websites
ISPs in the US were aiming to do that, since video traffic dominates the web pretty heavily now. But that could be easily abused, so they were slapped away with the net neutrality regulations, which iirc Trump rolled back.
I just don’t believe it applies in this specific domain any longer.
You referred to the megabytes thing in the past tense, yes, but the reasoning applied back then. In fact, gigabit speeds are still not prevalent worldwide (nor just in the US, from what I understand about their shitty ISPs). I can easily saturate the 100 mbps allotted to my cable-connection plan in the neighbourhood that doesn't provide much choice, and I'm pretty sure mobile connection isn't better than that in most cases.