(caution, I still rememeber college Statistics)😇
We are talking about "teams"....not individual "players". Keep in mind, the population of Indiana is larger today....big high schools are, well,... "bigger".
In 1980, there were about 5.5 million people. Today its at (or close) to 7 million, around a 25% increase. If we are talking about the top 1% of athletic genetics in the that population...
In 1980 that was 55,000 people
Today that is 70,000 people
You can extrapolate there are 25% more "great" players playing high school football today to fill out the rosters of high school teams. Even if the quality of each individual player is more or less the same.
The one statistic I don't have the effort to look up is the number of IHSAA members schools in 1980 vs Now. Although I don't suspect its gone up 25% (as population has), especially in the biggest classes.