Don't they traffic shape and have much lower speeds, though? If everybody in a building used mobile data at the full speed, where would the telcos put the base

Don't they traffic shape and have much lower speeds, though? If everybody in a building used mobile data at the full speed, where would the telcos put the base stations? And since the frequency spectrum is shared, how many handsets can a 3G or 4G base station even accommodate at once at a full speed? Unlimited data with tethering is a recipe for disaster; capped data plans usually do have tethering.