Those were some of my favorite events growing up.
One main key difference, however, is the entourage that comes with the NHRA professional show. Just looking at the 31 Fuel cars entered this weekend, for example. At a mid-2000s IHRA event, that would be 31 pit spots. This weekend, it will be around 60, and then you have to account for 5+ full hospitality suites that take up 3 pit spots each. Add on top of that a full manufacturer's midway, the Nitro mall, etc. and you're conservatively down 90 or more premium pit spots before you even start placing Pro Stock. IHRA would have been able to place their entire 5 class professional show in this same footprint and started loading in sportsman classes to fill out the rest of the property.
Edit - Typo.