Doesn't matter, the enthusiast crowd has popularized it enough that Foundry is all the shows up when you Google for a Pathfinder 2e VTT. Casuals Def look into what people are saying about different choices, so they're finding the foundry web page and the reddit discussions about roll 20.
Reddit is also pretty casual, especially when we're talking about a game like Pathfinder.
The problem with this is there is NO WAY most casuals are simply going to load this app that shows up on Google for no other reason than it's what some enthusiasts suggest.
Sure, the hard core players may be using it, but for most casuals putting foundry on has a multitude of problems.
#1 - Many who play online play multiple RPGs. If another app supports multiple versions in a much easier and cheaper way, they are going to that app over one they have to install/pay more for/etc.
#2 - When I look up playing Pathfinder RPG over the internet, the first result is NOT Foundry, it is a polygon article about doing it. The first Virtual program that shows up is roll20, than it is d20pro from what google seems to show me. Foundry only shows up first if you hit VTT in that. Then, when clicking on the link it brings me to a Pathfinder 1 link. I don't want PF1, it was PF2. I click on systems and modules, and it just brings me information on it, but not on PF2. It seems you literally have to subscribe to get access to know what they actually will support!
It's too difficult to find what I'm looking for...as a "dirty casual" as people seem to call those like me.
#3 - Foundry seems a tad more complex in how they portray themselves. It is hard to figure out where or what to find to play PF2e.
#4 - My experience with PF2e (mostly via the BB) was online. We did NOT use foundry, and if we had been asked we would never have even given PF2e a try. We actually did not use Roll20 either, we used a chat system with cameras to see ourselves and photos. I don't think Foundry is attracting a majority of the PF audience (I may be wrong), but then, there are MANY ways to play online.
But that's also the systems greatest strength, some gamers like having a lot of decision points and tactical choices. If you read the subreddit threads on why people left 5e in the first place, you see a lot of people actually value this kind of depth. Raw Complexity isn't a benefit, but the depth that can only be achieved by a little complexity used efficiently, as it is in Pathfinder 2e, is very desirable.
Depth is good, and there is a lot about PF2e to like. I like that fighters hit better than other classes. That Rogues have a ton of skills comparatively. That each class actually seems more representative of it's class than they do in 5e.
There ARE factors that turned our group off of PF2e though. Failure to recognize those factors probably hold PF2e from being more successful than it could be.
While Amazon or Roll20 probably should not be the ONLY metrics on how well PF2e is doing, and should be used with other metrics for a better picture, they ARE metrics. The do indicate that on some level PF2e is not selling as well as other things are. Amazon is a HUGE marketplace these days for physical goods (though PDFs sales would need to be seen otherwise) and to simply discount it without offering any other metric would seem to be trying to ignore what the numbers are.
That doesn't mean that PF2e is dying or doing terribly. Compared to 5e it is obviously not doing as well, but how about other RPGs?
A quick look (at this exact moment that I looked, meaning it could change when others look) the PF2e core rulebook is #7061 in books, while the Call of Cthulhu Core book is #18,988.
As I said, I think Amazon can indicate how well an RPG is doing in sales comparatively to other RPGs. Discounting it as a metric seems disingenuous.