I always have to wonder "why" that's the case though
my random musings would be that the overall talent level of the league back then was a lot lower, so your truly talented players could shine more. I very much do not believe there was just some mystical golden age that all the best players that have ever or will ever play just happened to be in, there is some reason why those guys reached those heights that goes beyond "oh they're just better than everyone else ever will be"
The talent level and atheltic ability these days of athletes is absurd and there is zero reason why any of these guys aren't as or more talented than Leetch, Borque, Potvin, even Orr. Waving our hands and saying "those guys were just special and we'll never see their like again!" is just an appeal to antiquity. But the average fourth liner these days is probably miles ahead of the average fourth liner back then. The average goalie is an absolute beast compared to the average goalie back then. The game has changed, the depth talent level is higher, it's absurdly difficult to constantly take over games like you're playing against peewees because even the worst players have ridiculous skills to anyone who's not a pro. That players like Makar and Fox can take over games and tilt the ice the way they do is amazing in todays game. That McDavid can do what he does places him among the elites to ever play the game.