“Some time in the 1980's any decent radio station had moved from the whistling and popping of mono AM to the crisp stereo sound of FM, and as a result pretty much all of them had added the “FM” suffix to show off how modern and fancy they were.“
I am not sure which country you refer to but, in the 1970’s AM listeners started to defect to FM Stereo. By early 80’s AOR stations popular and great KSAN in SF which started the free format, non top 40 like KMET popular in Los Angeles to Rock listeners started to devolve, were reformatted or closed. As far as I recall, internet broadcast transmissions were not a priority for most in the 90’s. The radio then at that point was not as important to discovering new music. I recently have read countries like Sweden even plan to shut down all RF transmissions.