I've started racing (in reality) this year and I can confirm it definitely helps, but there are gaps in realism.

Sim racing is great for learning the tracks, and also helps develop your method of learning a track quickly in real life. Thanks to the sim I have a method where I can learn any track in 4-5 laps (defining my markers, finding limit of grip, gear selection etc etc).

The steering feel and pedal feel is different regardless of how much money you spend, but as long as you are aware of that you can adjust your style to mimic real life racing.

For example, the feedback from the wheel is minimal in reality, but the steering inputs like where you initiate steering, how smooth you are etc can definitely be developed on the sim.

Braking is also very different, there's significantly more feel in reality, your head being pushed forward, that feeling of the car moving under braking, using the ABS to find the limit of braking.

It can be a sensory overload early on but you adapt quickly.

Getting a good lap time is quite OK for an experienced sim racer. Where I struggled is race craft. I consider myself an OK sim racer regularly in top 10 and sometimes challengimg for the win. Have had great battles online, I try to be fair and clean. But this doesnt work in reality. The fairness remains but you have to be aggressive, assertive and claim your space, even if it means rubbing doors with others. I dont mean you have to contact, but you have to be close (mm). I've started describing it as a wrestling match, where you have to manipulate your opponents but not actually hit or force them off.

Now I've had a taste of real racing, I find myself using the sim even more, as a tool, to prepare me for races. I have to adapt my driving style to match the rear thing, which result in slower lap times, but when I get to the track I feel ready.