I don't disagree with you, but this is a "circular conundrum".....An increased purse would require a larger crowd, which would require a larger car count. You won't get one without the other, but personally, I think that these days, getting the crowd would be the more difficult part of the equation.
Yes, the entire world had a really crazy situation thrown at us, last year, and we're just beginning to recover from that. Nonetheless, I attended two of the modified shows at Spencer's in 2019, and planned to attend them last year, which as we all know, were cancelled. However, based on my "guesstimates", despite good shows, the stands were roughly at 50-60% capacity. That level of attendance isn't going to be a financial success, to the point that would encourage a track owner or promoter to really go "all out", and schedule a full season of racing.
Sadly, the fan support just doesn't seem to be there, anymore. At the Spencer shows, in '19, again taking a "guesstimate", I would say that 60-70% of the crowd was over 50 years of age. The younger folks don't seem to have the interest that we "baby boomers" had/have. And the local newspapers cover only the "big league" racing, unlike the 60s and 70s, when they would cover the action at the local tracks, so that doesn't help, either.