I got in to model sailboats. There are a number of one design classes. They have to use all the same boats, sails, rigging etc. How they tune, and how much detail they get in to as they build thier boats can be a big factor on race day. It is still though, a class for skippers.
I see this with COT. It is moving to a one design class. There are a lot of tuning variables, and how you tune can affect how well the car performs. Still, the cars are very even, allowing for more of a drivers class.
The different classes have thier advantages and disadvantages.
I like the Cup series the way it used to be. Sure, one manufacturer might jump out in front. But then some restrictions, and development by the othe rmanufactureer evened it out. The whole thing leap frogged around from manufacturer to manufacturer. In the late 60's and early 70's, Ford and Mopar fought it out big time. In the mid 80's, Ford and GM battled it out. Look at what happened when Ford brought out the ne thunderbird in '83. Million Dollar Bill started running away, but a few restrictions and some better engineering by GM the next year tightened things up.
I think one thing they want to limit too, with COT, is the Superbirds and Talledega's got going scary dangerous fast before major restrictions. Saw that happening agin in the 80's. they can slow them down a bit with COT.