I love freeform games, but find that it can be hard to get people on the same page. Player A wants to play a gruff barbarian and player B wants to play gandalf.
I also find that without SOME level of challenge, that freeform starts to fall apart.
I have also found that most characters, crunch wise, in dnd-style games tend to be easily described in only two or three words.
Dex-fighter, trap finding rogue, battlefield control wizard, battle-cleric.
Deep down, if I say "Smart fighter" every single person will get a similar image in their head. If I say Charismatic rogue, we all think the same thing.
1. Fantasy character concepts are so ingrained in our minds that simply naming a class gives most people a similar concept
2. We can further define that said character class by attaching a descriptive word to it
3. We can make the broad statement that in a world of freeform and a world with low crunch stats, that ALL characters are of roughly equal "power"
Character creation crunch is limited to two words. The class and the stat that represents the characters special aspect. We assume a baseline for all characters of a stat.
All barbarians are strong warriors of brute strength and lower intellect. We don't worry about feats and builds. A babarian has access to all things that a barbarian would. A strength-Barbarian is seemingly impossibly strong. A Dexterity-barbarian is still incredibly strong, but unusually agile. An Intelligence-Barbarian is still incredibly strong, but is better able to plan, use skills, etc.
Characters are all of the same "power level" but can be better at different things. In a 1 on 1 fight, a str barbarian and an int-wizard are equally matched. However, as part of a party, each has very different uses, pros and cons.
Die rolling is an opposed d20 roll, modified by common sense and the story telling of the player. A player controlling a rogue that is stealthing behind an enemy to get a sneak attack would receive a much bigger modifier than a barbarian trying to do the same thing.
Die rolling is limited to fights and major game changing plot points. Die rolling is also limited to only a few rolls per event. This allows the game to move forward faster. A fight might be best 2 out of 3 or may be simply one roll.
We can also assume that most rolls are going to be wins, but only effect how well the character wins. A successful roll is an outright success. A failed roll is a success with negative consequences. "Yes you kill him, but he manages to land a terrible blow before you do"