Would you call the pyramids the most difficult engineering problems in human history? They had a whole lot worse tools. I wasn't taking into account how much easier the tools make it, just the complexity of the challenge.
It was about "Those are literally the engineers who worked on this, one of the most difficult engineering problems in human history, having nailed it on their first try."
And how the tools, materials, processes, and organizational structures to deal with those complexities do in fact make it easier than say the original Apollo missions.
Easier for the individual people, but not an easier engineering challenge. 150T to LEO reusability is a harder problem statement 150T to LEO single use.