Does it though? Not read the article but progress is not all about speed & heat times.
Without stats obviously but I'd argue that engine reliability is 75% better than 40 years ago.
Back in the day you'd have a couple of engines go pop a meeting, now, you'd be surprised to see one go pop in a month.
Engines now are properly on a par with with 80s tuned engines straight out the box.
Apart from engines, what progress is there to be had as frames / wheels etc are "improved" materials??
Bear in mind that race times are equal to or slower purely because of less material on the race surface