Boy howdy. That speaks volumes
If Nascar tanks, it's going to be a weird world where all these massive tracks exist and one of their main series/sources of incomes goes poof.
Hopefully a new less polarizing series rises up and brings road course racing to America. That would be cool
I think motorsports racing in general is in decline, there are more pay to play drivers than ever and not just in NASCAR...sponsorship is dwindling across the board. Companies nowadays are more risk adverse than ever and see these expenditures as unnecessary, frivolous and fraught with liability..
There are several notable closures on that list, some very recent...
15 Abandoned And Forgotten NASCAR Race Tracks