I remember when I was like in middle school or something and when I used a tweaked version of the Toon rules to play D&D-like adventures with my siblings and cousins. I always loved just plopping them in a dungeon and being surprised with the creative stuff they’d come up with. Those experiences, to me, defined seeing players do awesome things as the main appeal of being a GM.
I think Dungeon World appeals to me because it goes a step further by guaranteeing the players a say in the setting itself. This is actually pretty nice because the expectation to make a fully fleshed out setting kind of intimidated me from running games like dungeons and dragons, especially considering we’d usually be playing for one or two sessions. Letting players define the world around them takes the pressure of me and lets them feel more involved.