It’s shallow. Perfect example of choosing “style” over “function”.  We need to be able to find interface items--very small ones in a very cramped area where it overloads your visual system-- quickly. That’s it. 
Our brain / perceptions / visual system has evolved for HUNDREDS of MILLIONS of YEARS to optimize our ability to distinguish between “FIGURE” and “GROUND”. This is ALL LOST in the name of following a silly, shallow TREND. It will not be in style forever. Basic stuff. Whoever is running things over there is a total amateur. I can’t believe a product with such a HUGE user base is leaving important decisions to an inexperienced designer who knows nothing of perception & how our visual system works. I’m really annoyed that I wasted so much time even writing this, but It’s adding such unnecessary friction to my workflow is infuriating & I had to say something. Come on, guys.