Not entirely wishful thinking. Granted it wouldn't work for a gate driven sport like MLB and it would take a sea change in attitudes but with TV money there's a path to an NFL season played without crowds in the stands. It wouldn't be easy to get the owners to bite on a minimal or no profit season and would require a players buy in to reduce their contracts to the commensurate revenue drop but unlike the other major sports that depend on gate receipts football could do it if the principals came together.
I guess that depends on your definition of the 'heavily' yardstick. MLB depends on gate receipts for @ 30% of revenue, the NHL @ 35-40% and the NBA @ 25%. In 2019 the NFL cap was $188M and shared TV revenue was $274M per team. Obviously many factors go in to profitability but it's safe to say NFL teams have a helluva big cushion in the head start against loss compared to owners in other sports.