Claiming the game is "the most advanced racing game ever made" is big words.
There's "most advanced ever" tier things in the trailer, such as the way the track updates and the way the NPCs have their 24/7 routines, but to claim that title it needs:
- Better weather simulation than GT7 and similar games with drying lines and cloud generation
- Better physics and FFB than ACC and a ton of other games on PC
- Better race weekend simulation for a sanctioned series than F1 franchise
- Ability to change strategy midrace with proper simulation of fuel and tire wear like F1 and hardcore sims have (and GT7 does... except the fuel part)
When it comes to graphics features I thought it was a good trailer and the likely next gen exclusivity really paid off in the details, but Motorsport is supposed to be more serious and the serious racers aren't much interested in damage models, paint flying from the car, raytraced reflections (which are blurry and easily the downside of the showcase) and things that are, generally, fluff.
T10 has a history of overpromise and underdelivery and, if you go by the Forza streams, this game has been in development for 3 years, not 5, as it was in concept phase until early 2019. What's they're promising is a lot considering they have to make it all fit into the Series X's hardware, which will be 2.5 years old when the game is finally released.