One of the things that distinguishes a good (and expensive) driver from a less good and cheaper one is that a good driver has a wider and smoother frequency response, with fewer resonances and breakups as well as greater excursion with low distortion. Getting a wide response isn't difficult if one's prepared to accept a number of limitations, mostly with cone breakup and limited excursion. Equally, getting a flat even response isn't that difficult if limited in frequency range. That's why one can make a 4 or 5 way loudspeaker using relatively inexpensive drivers, each covering a smaller frequency range, but then the complexity and cost is moved to the crossover and/or multiple power amps in the case of actives.
I suspect the reason why most larger loudspeakers are three way rather than 4 or 5 way is that three way is a reasonable compromise between cost and complexity on the one hand, and performance on the other. Drivers have to be that bit better, but then there are fewer of them.
Large two ways are much harder to do given that deep bass requires moving a lot of air, which requires large cones or very long excursion, and an HF unit that goes low enough to meet a large bass unit is also harder to do well, which is why there are few large two ways, Tannoys are probably the best known, the new Heco Direkt is another, and how smooth that one is, I don't know as I haven't seen a frequency response plot.