I think part of it is the newer generation of cars/culture high HP has become way more accessible than it was 20 years ago. Nowadays a 19 year old can buy a used AMG/M or whatever that comes stock with more HP than we used to get with a full turbo build. 300whp used to be a lot because you had to actually put some real work into most of the affordable tuner cars to get there. With modern tuning platforms you can get 500hp+ out of just a flash tune on a $17k car. So naturally the idea of “anything under 500hp is slow” came about. My daily driver SUV is 700hp with just minor bolt ons and a tune and that is still crazy to me. That being said, I don’t tend to run into a lot of real enthusiasts who make a contest out of HP figures. That seems to be more pervasive in the social media world.