My initial impression of Pathfinder 2e leads me to believe that 5e's success is about to slow down quite a bit. There are quite a few D&D players that are not happy with the slow release schedule of 5e, and would prefer more crunch. Pathfinder delivers more crunch. In addition to a new edition Pathfinder has a new video game coming out that looks very impressive, while D&D has nothing modern or exciting coming in the near future.
The one thing that D&D has going for it is brand recognition. The public knows what D&D is. They generally do not know what Pathfinder is. Just like most people order a Coke to drink when they want a cola, even if they prefer Pepsi.
I think that Paizo waited just long enough to observe the primary critiques of 5e so that they can release a Pathfinder 2e that is "better" than 5e. So far I have liked what I have read about it. I would not be surprised if Pathfinder 2e steals a significant chunk of the RPG community veterans away from D&D, while D&D continues to draw newer players into the hobby.