It's not even about specifically making the MSQ more challenging though. Look at the erratic difficulty of dungeons throughout the years. Some dungeons have some eye watering trash pull to the point where the bosses (not trash pulls sorry!) are often the breather. And then you hit the level cap, get a few bits of gear and the challenge all but evaporates.
A well designed and executed game will have a difficulty curve that is reasonably smooth and consistent overall. FFXIV's is akin to a drunk stumbling through wet concrete before promptly faceplanting into the lamppost that is Extremes.