Very active game and community. If you look on YouTube you will likely run into a video by some guy saying why he's quiting the game and giving a huge list of problems with the system. Just know that the guy's own players debunked his video - he'd heavily changed the rules, complained about the things he changed, and flat out not told the truth in his video. But his video is still one of the first things that pops up when people look for info on PF2E so... assuming you're just starting to get interesting in finding info; hopefully I can head you off of that video.
PF2E does NOT have as vibrant of an 'active play streamer' community - things like Critical Role for example. And if you look for games on things like roll20 it will seem dead. That's because most PF2E players who play through a VTT use Foundry.
I do strongly advise AGAINST joining any game hosted on roll20 - GMs there have to keep paying fees to roll20 for every book they use plus I think a subscription, so you're likely to find yourself dealing with constant begging for donations. Beyond that, the PF2E community itself can also explain why roll20 is a bad choice support / quality wise.
There are 2 active reddit communities (maybe more, just 2 I know of), and 2 active discords named for the system, plus a host of others hosted by various publishers. Those 2 discords are great ways to find online groups and to gauge community activity.
The publisher is absurdly active. Multiple books per month. In addition there is a healthy 3rd party publishing community in 'pathfinder infinite'. The official published setting is extremely well supported and, in it'd second edition "Lost Omens" form - well done. There is at least 1 third party setting, that I know of, from "Roll for Combat". Probably more that I just haven't found.
They are putting out a "new edition that is not a new edition" come November... so I advise not buying the core rulebook, advanced player's guide, or game master's guide for now. Use online resources instead.