Given the same budget for speakers, 2 speakers will sound better than multiple speakers.
There is no free lunch.
If one has a budget, let's say, $10K for speakers, and they spend on 4+ speakers instead of 2, the quality and engineering on every aspect of the speakers will be most likely be diminished.
Cheap crossover parts, inferior cabinet material and bracing, inferior drivers, less time and effort on R&D, etc, all add up to inferior sounding speakers. Adding more of the same quality does not make it sound better. More impressive maybe, but not qualitatively better.
If you ever want to test this, pick up a pair of cheap used speakers, open them up and add some bracing, some Black Hole 5, swap out the cheap crossover parts (iron core coils, sand cast resistors, electrolytic caps) with better quality of the same values. And revel the improved sound quality.
Most mainstream manufacturers don't put any money into these things, because they do not show from the outside, so consumers don't see them.
Even some people that should know better, are often taken in by great looking enclosures and marketing. Just look at all the great press those crappy new SVS speakers are getting.