There is, however, certain minefields that Paizo completely fails to discuss.
The "shmush two encounters into one and see your heroes die" is perhaps the biggest one.
There are others. Nothing that bothers a GM with some experience and advance warning, but still.
Just a single example: you cannot feature a traditional resource depletion game in PF2 (without heavy modifications).
First off, the Medicine skill (and to a certain degree focus spells like the Champion's Lay on Hands
). If you play the game RAW, healing hit points is essentially free, though it might take up to an hour to regain maximum health. But more crucially, the game is clearly balanced on the assumption heroes enter encounters at full health. Also relevant: spell slots are much weaker during low levels than in any other iteration of D&D I'm aware of.
So I'm saying that a GM that naively populates a nice little sandbox with the goal of making the players sweat "how far in do we go before we run out of hit points" will find that any martial-heavy party can fight on almost indefinitely. (Just don't play a spellcaster)
And if this GM then decides "Okay so I'll ban or restrict Medicine" (etc), he'll instead find that the already lethal game becomes even more deadly. In PF2 it's just stupid to keep on adventuring if you aren't at least at 90% health, since even "Low" encounters can become hairy all too quickly when heroes start dropping left and right.
Okay, so this twice-bloodied GM now makes sure to only feature easy encounters (challenge rating Low or lower), while still awarding xp at a reasonable pace. But the reality is that a single fight can still
easily wipe out half or even all a hero's HP. So this only means the party will be brought to a complete halt at entirely random instances.
Again, not saying this can't be solved. But it is a multi-stage project to make PF2 run in ways it wasn't intended to. A game like 5E is much
more flexible in this regard. Variant rules in the 5E DMG really transform the game. Variant rules in the PF2 GMG, in contrast, just fiddle with details for the most part, not changing anything core to the experience and cadence of campaigns. (Proficiency without level is probably the only GMG variant rule worth even mentioning)
PS. For the record, if I were to help this poor GM, I would start by stating that PF2 hit points simply can't be used as a resource on longer term than the individual encounter. HP in this game emphatically model energy and morale (things that can vary wildly in a short time) rather than physical injury (things that can quickly go down but never quickly go up in the real world) if they model anything at all. (Just giving up and accepting hp is a game statistic whose only purpose is to provide entertainment is probably the best approach)
So you'd have to add concepts like healing surges to the game to model medium term exhaustion. Or simply settle for existing concepts already modeling this (such as the drained, fatigued or wounded condition).
The advantage of adding healing surges or something that doesn't exist at all in PF2 is of course that you can be certain there are no unwanted interactions with existing rules (and with 2000+ feats, it is not trivial to check). If you settle for the Drained condition, for instance, you need to determine if Drained from fighting too many fights stack with all the other sources of drained (which there are many), and if a simple Restoration spell gets rid of them as easily.
But you'd have to add wholesale new subsystems. Let me just note that the GMG does not contain any variant rules with a similar scope.
So again, not saying it can't be solved. Just that running PF2 in another way than the clear use cases (as exemplified by the official APs, and the Pathfinder Society) can be much harder than you think, and certainly much harder than getting 5E to do your bidding.