I'm pretty sure there are several teams offering OTA broadcasts. But, maybe I'm wrong. It's also not just Comcast. DirecTV aired all of those games, as well. I had DirecTV, but I'm also rural and don't have cable options. But I also wanted the Sunday Ticket package so I can watch any football games I want. When they switched to YouTubeTV, I switched. It was a bonus that they also had NBC Sports Chicago. But as soon as the Sunday Ticket switch happened, YTTV dropped NBCSC. I couldn't get the OTA because I was too far away from Chicago, but then they opened up hubs in neighboring towns to extend the signal. The Peoria IL feed allows me to watch the Hawks and Bulls for free now.
But, I'm not surprised by the 78% drop in viewership. I was as loud as anyone that what they were doing was killing their brand, especially before they created their streaming app. But then the streaming app was too expensive to purchase, or maybe I should say the viewing content made it not worth it.
I think these CEO's think people love their teams so much that their blind loyalty would uproot their most beloved TV packages and move to wherever the teams moved to. People are a bit more fickle than that. They already have their cable package and streaming apps, and are comfortable with what they have. Meanwhile, Comcast, and cable providers in general, is a dinosaur sitting around waiting for consumers to wise up and look for cheaper tv options. They'd be doing themselves a favor and continue finding ways to work with local regional sports. Maybe even find new local regional sports to air, because they don't really have much to offer that's bigger or better than the other options out there.