Yes and no. It's always been that way. Art styles change. Remember when all of the animes looked like Death Note art? Or the ones that were similar to Angel Beats?
The problem is that there are more now than ever, and most artists go the most straightforward path. Do you think people magically changed their goals? Nope, people are people no matter what era.
It's always been about money. The ones that did it for love were few. People have been selling out since before any of us were born. Well not me, since I am centuries old. But you get the point.
Right now, manga art is diverse enough. Although certain genres, for example romcoms, look almost identical, if you look at the variety in other genres, for example shounen, it's diverse. I think anime studios simply use the same style since it is cheaper to make.