You're right! I left them out because buying full-fledged games from big publishers, sometimes IPs that have been alive for almost as long as D&D led me to discover some very different games. Just in the last four years I bought and/or played things like Burning Wheel, Vampire V5, Lancer, Orbital Blues, Death in Space, Zweihander, Symbaroum, Tales from the Loop, Modiphius' Conans books, etc.
And there's still a ton of games I haven't touched.
But yes, if I bought some edition of Ars Magicka tomorrow, I'd get something that's really different. But I haven't seen nowhere as much 3rd party content for any of the games I've tried and bought then everything that's orbiting D&D. It's just that it felt to me that the OGL and the 3rd party products were kind of a promise of things being done a different way, and my realization is that its not.