Radios and antennas. More weight and power for limited usecases. In Apple and Google’s mind - replace your garage door opener with a connected one. You are talking about an SDR to allow multiple frequency ranges.
I personally would love to have an SDR integrated with my phone (and for operating in lower frequency ranges, just give me an antenna port next to the audio jack (oh, wait...)). But then again, a TX-enabled SDR in a popular consumer device? FCC would not be happy...