So what went wrong for Bally Sports?
Even before Sinclair bought Fox Sports RSNs many services had started to push back on RSNs, including DISH Network which said RSNs are some of the most expensive networks, but the least watched networks. Even growing numbers of streaming services like YouTube TV have dropped Bally Sports and other RSNs over the high cost and low viewership.
Now Sinclair is facing plans from major sports groups to offer in-market streaming. There have been rumors for some time now that MLB and the NBA have been looking at options to allow in-market streaming as viewership continues to drop. This could mean that MLB and NBA are looking to pull back rights from RSNs.
It seems that Sinclair bought Bally Sports at a very high price, just as the value of RNS started to drop. Add in 2020, when most sports did happen, and this left Sinclair without expected revenue.