What is the major adverse consequence of using RG-58 coaxial cable for a transmission line operating on the 70 cm band?

RG-58 is a small-diameter coaxial cable that is relatively inexpensive and flexible, but it has very high attenuation (loss) at UHF frequencies. The 70 cm band operates around 430-450 MHz, where the signal loss in RG-58 becomes unacceptably high, converting much of your transmit power into trace amounts of heat rather than radiated signal. For UHF bands like 70 cm, hams should use higher quality, lower-loss cables such as LMR-400 or hardline. Distractors like 'excess reflections' are incorrect because reflections are caused by impedance mismatches (SWR), not the cable type itself, and 'excess RF radiation' is wrong because coaxial cable is shielded.