I think there are three things going on here:
1) The incentives at the top are different. Younger talent can stilladvance their careers by being creative (in the broadest sense), but up at the top it’s mostly about managing existing assets and trying not to get fired before you get your bonus or earn-out.
2) Due to the strongly financially driven development of the ad industry over the past few decades, the people rising to the top were on average the more financially inclined, not primarily innovators and creatives.
3) Most top people experienced the early days of their careers when the ad business was relatively stable. They’re simply not used to the dramatic change the industry is going through and don’t have the intuition to deal with it.