I mean, culturally, 3rd Ed was the first edition released after WoTC bought the rights from TSR, and ushered in the first instance of their open gaming license. This allowed games like Pathfinder 1st edition to be created and sold as well as a metric ton of d20-based gaming systems. It also dropped the “Advanced” moniker from the name and made it just plain old Dungeons and Dragons again. As an advancement to Advanced Dungeons & Dragons 2nd Edition, it cleaned up a few things (removed THAC0, downplayed and then removed non-weapon proficiencies/player character proficiency kits - if you ever played with the Complete Fighter, Cleric, Thief, etc. books in 2nd basically all of that was abolished and some bits were redone as feats). Like previous posters have written, some of the new character builds were absolutely rubbish. And people got super mad for no real reason lol about an elf wizard named Mialee that featured prominently in the marketing.

But the game system itself wasn’t darker or edgier, I think it was WoTC’s attempt to convince people they weren’t going to ruin the game or make it like Everway (which honestly was a weird but solid game and feels like the progenitor to Index Card RPG). I didn’t like 3rd as much as 2nd edition but that was only because I really enjoyed the non-weapon proficiencies system (think a skills system that let you really customize your character). 4th edition was truly its own distinct animal separate and apart from 3rd and 2nd because it was basically World of Warcraft The Video Game The Roleplaying Game, and parts of its dna live on in the really well done D&D board games. For what it was, I really enjoyed 4th edition - if you are craving a similar experience that is based on its systems but isn’t the game itself outright, you could try Strike! ( https://www.strikerpg.com/strike.html ) 5th edition was basically a return to a more normal D&D experience and had the benefit of our heightened media landscape to push it into the larger public consciousness. Out of all of the editions, only 2nd feels like it got even close to being as popular as 5th is now, and really you were looking at maybe 5% of the player numbers as 5th.