Are you saying that sailing boats did not get better in 800 years of evolution? It looks like that and it just does not make any sense. Compared with those 800 years of evolution full keels are very close in performance to fin keels
What I am saying is that the Carrack was a huge step back and we didn't develop a sailing vessel as well designed as the Viking longship, again, until around the 1800's. There was a gradual change from the carrack to the brig, but it took a long time. And brigs aren't exactly models of performance.
Yes, there were some, small traditional craft, like the faering, but ship development, as a whole was set back. Imagine how things might have developed differently, if the launch point, for development, had been the longship and not the carrack.
The longship has a lot of features of modern performance sailboats: the narrow entry, the wineglass cross section, the shallow draft ( of the actual hull, not the underwater foil ) at the mid section. If you cut a longship in half, it would resemble some of the new racing boats. Definitely a better platform for sailboat design growth than the carrack.
That's what I am saying.