Plastics have gone from niche to absolutely ubiqutous worldwide in ~100 years. Even if it turns out to be totally and completely harmless to humans and every other animal, wouldn't you want to know that for sure?
So have radio waves. There was a lot of paranoia back then, much like with plastics today, and a similar amount of studies showing that exposure to RF radiation causes cancer, but that has mostly died down as people realised the truth.
As time goes on, the harmlessness only proves itself.