FRS and GMRS are line of sight. Great reception out in the open deserts but pitiful in an area with things like hills, trees, or tall buildings.
Power output for hand held radios is limited by the FCC but there is no agency that polices what manufacturers advertise on the radios that they sell.
GMRS covers a family so two families will require two licenses to be legal - if that is a concern to anyone anymore.Amateur radio covers only the individual who has passed the required test.
The FCC has been in the process of deciding whether to stop charging for GRMS licenses though this has been going on for 3 years and still no decision has been made.
The only place where I have found a CB radio to be useful is on logging roads during the harvest season. Signs are posted as to the channels used on a particular road and by monitoring it you will know when a truck is headed your way and they are not going to be able to stop when the get to where you are.
I have had cell reception with Verizon, even if it is only 1xRTT, in 99% of the western USA where we have traveled. Before the switch to Verizon and with AT&T I frequently lost service once outside of towns.