I had some involvement in sims a few years ago, ending up with an article in a certain magazine.
The person who was responsible for getting the flyit sim certified was an aeroplane CPL who did 11 hours in the sim, 20 minutes in a real helicopter then took the CPL flight test and was told that if he had had the hours he would have been given his licence then and there.
But technology has moved on - the flyit was dead basic. I have a 206 sim here with proper controls and panels being used with the Oculus Rift (VR thingy) and a leap controller and the results are nothing short of startling, even with the FSX Beaver.
You can see there is a long way to go, but you can also see the potential. With X plane 11 on the S-76 you can even do NVG stuff. if I can get this pesky force feedback joystick working I will have a longline sim up and running.
So, they do have a purpose - to my mind, even though they are not exact models (and FSX/Prepar are dead in the water these days), they do make the time you get in a proper helicopter so much more productive. Athletes and musicians practice the same thing for hours on end - we don't because the costs are high, but when you have a sim costing $15 an hour to run, that improves things a lot.