He obviously is the best striker possible - in the league, but also is he worth 100MM or are there better options? But the guy has proven time and time again that he struggles in big games. His UCL record: 5 goals in 12 games. That is unacceptable for a 100MM striker.
Cavani good for Ligue 1? The guy is Serie A proven. Anyways: there is only one stat you need:
He had 8 goals in 8 champions league games. He put in 2 goals over 2 legs in Barcelona.
Lacazette? I think that argument is weak. The supporting cast on Juventus is dramatically superior to that in Lyon and more, it isn't logical to pin a disappointing year on one player. That being said: he isn't proven for a big team, but also he wouldn't cost 100MM.
Benzema? For 100MM I think Real would sell him last year. He isn't a pure striker, but he put in similar UCL numbers as Higuain in a support role.
Griezmann? Not sure how they are so similar. Griezmann is a direct, quick, technical winger/striker. Dybala, a creative technically gifted trequartista/ secondary striker. It would not be redundant to have both since Griezmann would play higher up the pitch. He certainly wouldn't be as involved in the build up. Just comparing heat maps shows this.
Falcao? Last summer he would have been cheap. Sure it would have been a gamble, and it's definitely hindsight being 20/20, but he would have been inexpensive.
My point is I think there were better ways to invest 100MM. Higuain is a great striker, but his propensity to choke in big games is quite documented. I'd rather have seen less money invested in a younger player.
Also, coming to camp out of shape definitely put a bad taste in my mouth after such a huge transfer fee.
Was he a bad signing? no.
Would Morata have been better at the same price? no.
But were there better uses? Or better deals? I think probably.