I've visited a decent amount of datacenters throughout my career and noted there's still a good amount hardware out there that fall back on 3G as well as traffic cameras.
I wish carriers were more interested in truly expanding their network coast to coast instead of drag racing speed tests. I can hold a Discord call driving in the hills from Seattle to the Oregon border no problem but am without service/roaming for an hour on flat I-76/I-80 from Colorado to Nebraska.