The way it works is like this -- consultants like these have to have a good reputation. They are effectively the sacrificial goats to absorb failure. If the project fails everyone can say "but we had the best of the best doing this, if they failed, surely nobody could have done it better". In that model it makes sense to hire the most prestigious candidates.

Also remember clients also have their own bosses, board of directors, investors and supervisors to answer to.

It seems with Palantir it worked well with CIA. If you ever sold anything to Uncle Sam, you know he loves to pay lots of money and then pretty often it ends up not being used or forgotten. Guess they tried that with a few big companies but found out that Coca-Cola is not as careless with its budget as Uncle Sam, and \had a hard time convincing them to just throw away tens of millions on some analytics thing.