Nobody is claiming that money managers have omniscience.

What they do certainly have is more information and expertise than a random internet commenter. They don't know everything, but it's safe to assume they know more than you.

Well the actual decision-making tends to be more important than just what one knows. A pile of cash seems more indicative of investment paralysis than some grander strategy. Like, "we can't figure out the best investment to make with this money, so the safest thing we can do is hoard it until we come up with a better idea".

Again, this is pure speculation. You have approximately 0% of the information available to the people who make these decisions, so why bother guessing? It's boring and pointless.

I would argue its actually kind of fun to speculate, but fair enough.