The current state of ND football is better than it has been in 30 years. That was a different era.
Kelly has run a reasonably clean (though far from perfect) program.
He is a good, maybe even great coach. Probably in the top 10% of active coaches. He is not, in my opinion, in the top 1%.
As long as he keeps winning 8 or 9 games per year, and graduates his players, he likely has the ND job for as long as he likes. I personally wish there were higher aspirations for the football program, but they don’t ask my opinion.