Librem/Pinephone's killer feature is going to be the baseband modem kill-switch. It's going to be the only way to opt out of this category of tracking.
I imagine people caring about that could be shopping specifically for (any) pre-5G phones and networks. Might have an effect of holding up the deprecation of 4G as the first mover network will be economically punished.
I think you vastly overestimate the amount of people that really care about this and won't just get the latest iphone/Android they can afford once their old phone's screen is too cracked and the battery too aged.