As always this is a tough question, i feel like "how much of a sim" conflicts with "how good of a sim" at times...
I mean Iracing(just using one example, don't jump on it fans) aims for full realism, but how much of that it delivers?
Anyway i feel like they aimed (a lot) higher in terms of driving realism than previously in the series, it is a lot more involving than the previous ones.
Could they have pushed even further? I would say yes, specially given the sales success of something like P Cars that, imo, is a further step ahead in the sim-scale.