The underage sex was just the bait. And Trump was a full partner in this thing. Remember Roy Cohn taught Trump haw to do blackmail and extortion, and Trump has done that every day he has been in the White House.
If the truth ever gets out, we will learn that Trump's role in the partnership was to recruit "all the best people" to take the bait. Maxwell's role might have been to market that kompromat to the various spy agencies her father knew so well. And of course, some of those customers (spy agencies) were the selfsame people grooming Trump as a Russian asset while simultaneously keeping his businesses above water by steering lets of money laundering transactions through his casinos and real estate.
I believe all of the above is 100% true. But even that does not seem to explain why Trump is fighting so hard to block this information, because a good part of the above is already public knowledge. I can think of several reasons that Trump would be digging in, but that is more speculative than the above, so I'll leave that for now.
We should be asserting what is likely in the files. If we have that wrong, then Trump can easily disprove it by producing the facts.