The decline continues...

I disagree.
Rules changes that drove Mopar and Ford from Pro Stock.
Short fields in the pro categories.

I (sadly) think they are on the decline.

I agree now. But that is recent. NHRA fans are getting older while drag racing fans are getting younger. Go to a no prep race, radial race, street car event. The stands are filled with folks that are under 40. A YouTube drag racer just sold out Lucas Oil raceway in Indy with a street car race and a burnout contest. South Georgia Motor Sports Park is insane during the lights out radial races. Folks are tired of the NHRA and the Nitro stuff isn’t cutting it anymore.