Basketball has evolved in iterations, looking for one year in particular is pointless, but I think the overall increase in the three pointer is the biggest change of the more recent ones.
Like evolution itself, it's usual slow and gradual and not well perceptible on a day to day, but is when comparing now to say 20 years ago, or 20 years before that.
Basketball hasn't been a sport in decline in participation like boxing or whatever, it actually became much more globalized and money in the sport has exploded, perhaps gaining most momentum during dream team and Stern's intentional globalization initiative. Talent is deepest now, deeper than it has ever been. Things like dunking from the free-throw line which would get all sorts of hype and coverage in the past is a roll-eyes thing now.
Statistical analysis also showed the inefficiency of how the game was played prior with the perimeter two point shot being used too much in the past. Now the entire court gets stretched out, even some bigs are three-point threats. It's laughable to me when people suggest some team from the 70's through 90s that makes 5 three pointers a game is gonna compete with modern basketball teams filled with sharp shooters today. They also over-estimate the "toughness" of the players back then relative to today; yeah there might have been more hard fouls but so many of those players of yesteryear that were "big" , were big for then, not big by today's standards. That's not even getting into things like amount of schemes being run today etc.
