HAM radios often require reasonably large power supplies to spit out the large wattage signals required. Remember, a cellular phone only has to talk to the nearest cell tower, which are legion in most areas, so your phone won’t spit out more than 1-2 watts (dependent on the SAR in your territory).
Your HAM radio idea means talking to anything other than the relatively small number of operators near you — and you can guarantee that compared to the cell tower population, that number of operators will be frighteningly small — means you’ll have to up the wattage. This can be as much as 1.5kW output for operators with big PSUs and large antennas (oh, don’t forget the antenna, which could have to be a couple of building stories tall to work). And I wouldn’t want a 1.5kW antenna anywhere near my head.