The problem Indycar has is they charge a big sanctioning fee to the promoter AND pay no tv money. Venues struggle to make any money on the races.
Due to the big tv money, Nascar races makes profit before one spectator buys a ticket.
bigger issue is lack of sponsorship....when open wheel screwed themselves in the mid 90’s the sponsors said “see ya” and went to NASCAR...NASCAR has a business plan- Indycar cross their fingers...