Modern mobile processors are extremely powerful, and way more power efficient than desktop chips. Many Linux distros have ARM variants.

And (AFAIK) it’s mostly because they are tuned for that, whereas laptop processors outside Apple have some overzealous boosting configs/clocks these days.

You are not wrong though. Developing and supporting them (as a company) would be very labor intense, so no one really wants to make that jump beyond Qualcomm/windows.