I think it's possible that mecha is still in a lot of anime but mecha is no longer the centerpiece, it's just part of the everyday world in the story.

Consider the Avatar movie, and the most recent installment Avatar: The Way of Water. The original Avatar came out about 13 years ago. Even then, the mech suits were just part of the collection of high-tech military equipment in the story, and the story certainly didn't revolve around it although it was prominently featured near the end. In the second movie, it was simply there as a minor element of the background.