Thomas Shey
Legend
Exactly. For many, many, many of us, D&D has been a different game. Dramatically different rules, dramatically different experiences, and new games are trying to compete with that multi-generational history of creativity and maleability.
In which case, you might as well be comparing D&D, Runequest, Fantasy Hero and Dungeon World for all the cross-utility you're liable to find.
D&D players today play different amalgams of all previous versions coupled with different combos of house rules. It is what it is. That annoys a lot of people who dislike D&D and want to develop something different but it feels like they're aiming at a moving target, which they are. That's why it's so tough to compete with D&D.
If you're under the impression only D&D GMs make house rules, or that only it has had several editions, let me disabuse you.