"Dungeon World" is a good transition from D&D to PBtA-based games

There's a thing about D&D - it's actually a wargame. Big share of its rules is tailored to tactical combat. "I go forward for 3 squares, use this ability, use that ability, end of turn" - that kind of stuff. You can play without it (system is a tool, yes) - but in that case you throw off half of the game rules, so what's the point? Anyway, there's nothing wrong with it and there're many people who seek for just that gameplay style.

D&D is the most famous game system due to enormous amount of money spent on it by publisher / copyright owner, and it lasted for decades. But TTRPG is much more that that.

There's TTRPG design framework, called "Powered by the Apocalypse", or PbtA, as the first game made with it was "Apocalypse World". Here's a short list of PbtA features and principles:

• it's narrative, which leads to making and telling interesting stories
• "Fiction first" principle - player don't use character abilities like pressing button in videogame, they describe what they want to do, and that description (possibly) triggers a move
• Moves system. Moves are NOT abilities. Their goal is to make emphasis on key game aspects. When you trigger a move - it matters!
• "Fail forward" principle. When player fails a roll - GM makes a move, and story takes a turn. Player gets XP for failing,
• "Play to find out" principle. GM doesn't know what will happen. Players make the story together.

Dungeon World is a PbtA game with strong D&D flavour. That means, it has kinda familiar character classes, races, and atmosphere - full of dungeons, taverns, orcs, goblins et cetera. But it plays vastly different. It's rules-light system, easy for new players, but somewhat demanding for the GMs skills.

As for me personally, I was using reddit for its DW sub mostly, but now it's still in blackout.