This is probably not a very popular and might even be a little too in the weeds for macro level discussion. I actually think there was a bit of a "micro downburst" in league quality from roughly 2009 or 2010 until somewhere between 2015 to 2017. It was a recoiling against the hyper-speed game that came out of the 2005 lockout. The game became too fast for its own good and actually had a negative effect on quality because of the comparatively few players that could play with the puck at speed. Mostly because those players grew up in a slower game and while rule changes are quick to be pushed down to youth levels, the development and coaching advents are not. I'd wager that around this time, it was as close as the NHL and KHL ever got (which isn't to say "very close", just as close as it got) in terms of league quality.
It wasn't just limited to skaters either. Goaltending got very low during this micro downburst as well, as the high end talents started to age (hell,, Brodeur got to a Final at age 40) and a wave of new goalies had yet to really take over. I mean, Christ, we had a Michael Leighton vs Antti Niemi Final, we had a minor leaguer win two Vezinas, etc.
It's still a little difficult for me to figure out if it felt as down as it did because I lived it every day, would I consider it so pronounced if I didn't? I'm not sure on that yet because I'm not sure if I've seen the peak of the current era. But this game right now is markedly better than, say, the 2010 season.
Also, this isn't to say that 2010ish is anything nearly as bad as the early 80's or the WWII era, not even close...but it's not as good as the seasons immediately coming out of the lockout nor the last 5 or so seasons for my tastes.