Say hello to the elephant in the living room!!
A huge component of this discussion has to do with an indictment of the current coaching culture. Some folks (including former WTA and ATP pros) make a strong case claiming that too many big-shot coaches have abandoned the long-term goal of developing players with complete skill sets. Instead they go for the shortcut to success by training their kids to hit big strokes and serves that turn them into local winners in a big hurry. These coaches churn out "winners" and more folks in the area sign up their kids. Lather - rinse - repeat.
But that training approach leaves the attacking portion of the game, including S&V play, as an afterthought. When kids don't learn that stuff early on, it's tough to reinvent themselves later on and many just stick with what they know.
Each time I see a WTA match where two bangers just hammer away from the baseline, I chalk it up as another exercise in stupidity. Time and again we've seen contenders go out against the best like Serena, Sharapova, Azarenka, etc. (when they were at their peak) and those hopeful challengers did nothing more than try to outgun those big hitters from the baseline - no Plan B. No mystery as to who dominated, right?
Now that there aren't those few dominant baseliners anymore, we routinely see these upsets around the WTA at every tourney. It seems to boil down to not much more than another case of who got hot for this or that tourney. Good for you, here's your trophy. But nobody can stay hot for long and stay successful in a mode of play that's too much of a 50-50 proposition too often.
Hard for me to believe that this strategy of more-of-the-same has endured for this long. Aggie Radwanska took up residence in the top ten for a long time and even cracked the top five for a long stretch with all sorts of variety in her game, but none of the baseline power or big serving we saw among her peers. The one who is giving me a lot of belief is Ashleigh Barty. She's not a pure serve and volleyer, but she can do that and also attack a short ball as well as anybody around the WTA. Her "sudden" success is no surprise to me at all, but I'm still waiting for a generation to wake up and get the memo.