Hell, go watch just a couple laps from Texas in 2002. Dirty air was a huge topic that year, the last year before they standardized the front and rear bumpers, and even then, drivers can follow and get runs in corners. It's very much a next gen problem.
I went to NASCAR Classics, went to 2003, & clicked on a random race at Texas (a Track renowned for terrible racing even back then) and screen recorded a few laps. So this is not even me cherry picking examples because I’m sure there are far better examples. This is just how it was. You don’t have to search for examples. The racing was just good.
Watch the 12 car here as he keeps entering the corners directly in the wake of the 8 as he chases him down for the win, & experiences little to no dirty air. If he entered the corners like that in today’s car he would lose the nose and push up 3 lanes.
It’s jarring how drastic of a difference this is to today. Yet we are told it is exactly the same. You can click on literally any race from 2000-2009 on NASCAR classics and find hordes of examples like this from each race.