There is not much to the design of a headset. A simple bearing that smooth's out the steering of a bicycle. Parts that can be removed and replaced if necessary. Clean and smooth in design and sealed enough to keep dirt from entering the lower bearing race from the front wheel.
slight changes over time, the Raleigh design remained somewhat the same for years.
That said, with all the improvements in the world today and how much better living standards have supposedly become, it really bothers me that the headset on my new Specialized lasted only 7 months when the Headset on my Golden Arrow is still working fine after 70 years!