I think there is a lack of games like Driveclub or what NFS was in the 90's.
That's why the terms sim-cade and sim-lite exist. There is a spectrum from pure arcade to pure sim. It's why you get people making pictures like this.
This is not controversial. This has been how these types of games have been categorised for decades, and if you go into the Gran Turismo forums you'll see endless discussion on whether a given version of GT is a full simulation or only sim-lite.
If you want to make up your own definition of what "arcade" is then I can't stop you. But most people find that having fairly solid definitions of what these terms mean is useful when discussing and comparing games. And the definition for arcade games is that the physics exist purely to serve the gameplay and any resemblance to real life physics is mostly incidental.
That doesn't mean that the physics can't be accessible or deep. Depth has nothing to do with realism. Trackmania has incredible depth, and it's pure arcade.
Credit to ViperConcept for the above chart. I don't necessarily agree with all his placements, but it's a clear example of a concept you obviously haven't come across before.
The point of an arcade racer can be many, from offering ludicrous quick action with no care for realism (Burnout 3) to accesible handling model with a certain depth to it.
And what separates the way those games do their thing compared to simulations? How realistic the physics are. You're talking about gameplay. The gameplay is a by-product of the physics, for racing games at least.
So yeah, I completely disagree it's a matter of me not knowing what an arcade racer is or supossed to be. I definetly wouldn't try to state that an arcade racer should be certain way, but the industry is siding with a particular style because money.
Disagree if you like. You're still wrong. It's not about stating that an arcade racer should be a certain way, it's the fact that the term "arcade racer" exists to describe a certain type of game. If a game is a certain way, it's an arcade racer. If it's not, it's not.
If Unbound ends up being like Driveclub or Forza Horizon to drive, it'll probably get labelled as a sim-cade. That's why you saying
"devs have more and more some kind of fear to make reasonably realistic physics for arcade racers" is just silly. You can't put reasonably realistic physics in arcade games, because if you do it's not an arcade game.
This is basic use of language. It's like saying that you don't understand why Toyota doesn't make more black cars that are coloured yellow. These things are fundamentally not compatible, it's one or the other.