I don't think most people really understand the compute complexity required for LTE and 5G terminals. It's telling that pretty much every discrete-ish full-speed LTE or 5G modem I've lain eyes upon is actually an embedded SBC running its own OS, with attendant power requirements.
The companies do that because by far the largest market for LTE/5G modems is smartphones.
They could make a more cut-down modem chip, but why would they? They already make hundreds of millions on smartphone SoCs. Just rebadge that silicon as modem ICs, no one cares that an LTE stick runs full Android.
