Worse on what ?
Netcode ? NHeat's netcode is still among the best out there.
Graphics ? Do the screenshots looks like 2001 to you ?
Physics ? Check yourself, it's free.
AI ? Definitely not NHeats topside, but no worse than LFS AI
There's some reason NHeat is still in use. And this is not just because the game engine is available for free (legally !)
It's more simple: Magnus has a very detailed expectation of how sim racing should be - actually about as close to real life racing as could be.
If some environment does provide more "realism" in this particular aspect, other environments will be either "outdated" or "on the wrong way" - they'll simply lack what he's looking for. And as he's the one with full insight in what simracing has to be about, those other environments will be turned down in his ASS pamphlets
Welcome to the club
Right now he's simply the prophet of "pay for race" environments, as only these will ever be able to provide what he's looking for. iRacing should try to hire him ASAP for public relations....