Based on the fan talk, the conventions I have been to and Paizo's responses, plus actual sales, it looks to me like it achieved its goals of providing a new system that is
- Easier to learn and run than PF1, but not as easy as 5E
- More depth and options than 5E, bit not as complex as PF1
It was clearly designed to fit this gap, and it seems to have done so. If you have learned PF1 and don't think it is is clunky and hard to run, you'll stick with PF1. If you find 5E gives you plenty of options and honest feel constricting, you'll go with 5E. But the evidence shows there are a lot of people who are in the camp of liking the simplicity of 5E but finding it a bit lacking in depth.
This, to me is a good thing. Competing with 5E might be that business-wise, but more importantly to me it would mean a waste of design space. 5E does what it does well -- we don't need a clone. The designers of PF2 looked at where there was a gap, and they provided a game for that gap. Some people want something in the gap, some don't.
I've never been in the camp of those who feel passionately that there is One True Game that everyone must play. 5E is a great game that I will happily recommend to most people, but I don't want to play it. And that's I think PF2's appeal and success; new players will be happier with 5E because they don't worry about breadth of options. My favorite D&D version is
13th Age because I like the way the designers tie the core elements of D&D with modern sensibilities that focus on narrative. It's the "D&D for people who lean to narrative". But my second favorite version is D&D4E, as it is D&D where it's all about the game play and extreme depth of tactual combat. I'd never recommend it to anyone (except people who come from the war-gaming community, maybe).
I used to play 5E at smaller conventions as I preferred it to PF1. But I prefer PF2 to both of them, so now I've switched to that. At the moment a lot of people are still committed to PF1 and so that community is still large, but over time my expectation is that those people will move to PF2 rather than 5E, as it's closer to what they want. PF2 is never going to be the "instant lightning" of 5E, which benefited from being the first new version of D&D that wasn't super-gamist since 2000, released at the same instant that nerd culture became cool. It's an evolution, and so adoption of it, as a previous comment mentioned "a slow burn"