The flat, dead interface style was not great, and has run its course. It’s time to move on. Liquid Glass was a good start, but kept too many flat and low contrast elements to be great. I had hoped for Apple to push forward and refine the design until we had more depth, colour, and contrast, but now they’ve gone backwards to bring back more flatness!
I know that on this forum I am in the clear minority, all the angry and disagree reacts make that perfectly clear, but this all just highlights to me that something new is needed. Keep some signature interface touchstones such as the menu bar at the top of the screen, Finder’s face leftmost in the dock, and a few others to preserve the identity, but rework everything. Do a Mac OS 9 to OS X level shift.
We need to bring back some things that have been lost along the way too, such as a clear and obvious places to click and drag to move windows around. Apps don’t need to use 100% of the windows!