They were not just focused on the tanks. That was one component of the structure which involved Spacex testing propulsive landings using test articles of varying designs. . And this is the crucial part. . . While designing those test articles and iterating on the manufacturing systems AT THE SAME TIME.
The tanks are silly to make a point about was the response above if that was unclear. It was one component that was going through changes with the rest of the system in a revolutionary way that has never been done before. Not during the falcon development process or any other rocket development process going back to the Apollo era.
Blank sheet -> Starbase today is ridiculously complex. Each element in of itself that I outlined above takes YEARS. Arguing in a silly way about “oh my, they did take two years, well, technically, kinda, with these caveats” is such a stupid way to approach the measurement of progress where , while being completely wrong , is also not constructive to the discussion.