Couple of thoughts after morning coffee.....
First, maybe after a 100 years of intensive study and practice, gca has become a "mature" industry, not unlike Tide and Clorox, etc. Any refinements will be incremental, especially given the standardization by the USGA and others, like par, distance, handicap, etc., where others have vested interests in keeping things more or less the same.
And, design, by one definition is art that someone has to live in or make use of, i.e., has a function. The basic function of golf hasn't changed in centuries, the scorekeeping remains mostly the same, etc. etc. etc. How much can courses change if they are really, functional arrangement of the ground for the purpose of making it useful for golf?
Last, not to mention it is a business, and usually a struggling business at that. How many courses can afford 29K SF of sand bunker on one hole, when many have that over 18 holes? In my 43 years in the biz, I can usually predict which bunkers will be removed, and without driving up there to see it, figure after the award season, marketing photos, etc., much of that bunker will be removed, if it follows typical practice and/or the PGA in Texas doesn't turn out to be the financial bonanza they thought it would be. Time will tell, but I am sure at least one project manager questioned it already as excessive.