Everything in all levels of racing has always been introduced to make the car easier to control, easier to go faster in. Suspension, brakes, aero. This is all very obvious. So it makes what those drivers of days gone by did that much more impressive.
You won't convince me that it's every bit as difficult to drive, say, a modern Porsche GT car as it is to drive a race prepped 930 Turbo. Tire technology alone has increased adhesion and wear intervals immensely in motorsports.