> 80% of radio stations in the U.S. are owned by one company(iHeartMedia, formerly ClearChannel)
They own the most, but it's not 80% (perhaps they cover 80% of listening markets). They own about 850 stations[1] out of roughly 10,000 commercial stations[2]. However, your point does stand as the second largest owner, Cumulus Media at 455 stations also filed for bankruptcy[3].
[1] https://en.wikipedia.org/wiki/IHeartMedia
[2] https://docs.fcc.gov/public/attachments/DOC-352168A1.pdf
[3] https://www.nytimes.com/2018/03/15/business/media/iheartmedi...
