Who can provide holistic advice then? Maybe a management consultant, or a frequent reddit user? Plenty of scientists know about things outside their laser-narrow domain.
Why would you consider there to be a need for experts to provide holistic advice at all? It’s pretty obvious when somebody is trying to give you advice outside of their (often narrow) domain of expertise. Scientists do it all the time. So do software engineers. I’m sure we’ve all been in, or party to, a situation where an engineer is frustrated that the business is not taking their very sound technical advice, somehow oblivious to the possibility that the problem they’re concerned with may not matter to the business at all.