3-Ways

When I first got into car audio back in the 90's, I picked up a pair of 3-Way Boston Acoustics for a little over $120. And I seem to remember that there were as many 3-Way Separates options as there were 2-Way. Ever since getting back into car audio about a year ago, I have noticed that 3-Ways are now few and far between and are rather expensive when compared to 2-Ways. What caused the loss of love for 3-Way Separates? Was it figured out that there was no need to separate mid-bass, midrange and highs? Or was there an improvement in designs that made this method unneeded?