That's not the case for me atleast, because I use a lower button control rate so that smoothens up the input by some distance and enables brake and throttle more smoothly which makes driving somewhat easier.
Also I have to disagree, because I was using a wheel before mouse, but now when using mouse I am quite a bit faster than I was with a wheel. That might be down to experience though because I wasn't too experienced when driving with a wheel
I do remember though that when I was a wheel driver then I would try mouse sometimes and would think how anybody could even keep a car on a straight line with it
All of this input precision and ability to drive the car to the limit comes down to experience and practice IMO (as with a wheel ofcourse), because I don't think that you could drive fast instantly when you start driving with a mouse. For me, having a wheel probably helped it a bit but I remember how useless I was when I first started driving with a mouse about a year ago or so, and then suddenly after some months of practice I was beating my old PBs with ease. As S.E.T.H mentioned, mouse drivers have to feel different things to drive fast and it takes time to adapt to that. I don't quite remember when I was competent enough to drive stints consitently, but still it takes a lot of practice and time.
What I'm trying to say here is that mouse drivers are often underrated and bashed because people think that it is very easy for them to do what they do, but I definetely don't think so.
I don't think that's really correct because I use so called wheel setups with mouse and I see no problem with them, except maybe for small details like brake pressure etc.
I have also given my setups to wheel users and I don't recall any big issues with them, except for maybe these small details.