My first track car didn't have traction control and the ABS would go off after a few sessions when the car got hot... along with my second gear. My second track car was undrivable with it's primitive traction control on so it had to be turned off but then it was so prone to snap oversteer it was a handful all the time, no big deal in a slow turn or long sweeper but add elevation with the suspension loading/unloading mid-turn it was scary. Heck, I spun it in the dry getting groceries.
Today's traction control from Porsche is really great. It allows enough slip front and rear for the driver to point the car intentionally and it is mostly off unless you do something stupid and then it'll jump in and flash at you when it does so you know it saved your butt. It's only come on a couple times for me and I was glad both times it did, I think of it almost like a training aid as much as a safety system. There are some subtle things the computers are doing in the background which I don't love like grabbing the inside rear wheel to make the car turn in better but really it's probably no more "artificial" than rear wheel steering or modern torque vectoring. The only time I turn off the electronics at the track is if the track is wet, there's no wet mode and the computers aren't up for going faster in the rain.
That said, I don't think all your knowledge is wasted in a modern car. Knowing how to drive the rear engine will still result in faster lap times, but now more people can enjoy the rear engine car without ending up in a ditch