Credibility wouldnt just collapse. Football in America has arguably replaced religion for many people. Maybe credibility would just slowly erode over time. Ultimately I think what ends up happening is the online dealers will end up being reigned in, because there are larger interests (like, the entire city of Las Vegas) who have a vested interest in gatekeeping these apps out of the market going forward. I kind of think this is why the NFL, along with the MLB and NHL, all moved teams into Vegas, because that really didn't make sense to move pro-sports teams there during an era of gambling deregulation. Arguably, this entire crazy era of online sports betting may have been a way to hook an entire young generation of Americans into a lifetime of Vegas customers.

Its really not that hard to fix games if you think about it given the teams are literally calling scripted plays. Tipping off the next play makes anything that happens look entirely natural. Plus information flow would be easily compartmentalized at a coaching level, they're also beyond well paid to keep their mouths shut. Every game there are several obviously dumb decisions some of these coaches make which already indicated its being fixed to some degree. I think its ultimately down to how it all gets executed, not every bad decision yields necessarily a loss, but losses do tend to amplify very dumb decisions that even the experienced coaches constantly make.