Granted, not everyone might see them as good, and a lot of people’s opinion probably comes from other people talking about them rather than experimenting with them in a real game.
Without going into details, and save for the few early levels, during which you might have seen a few skunks being conjured to great effect, a top-level summoning slot brings up a creature between 4 and 5 levels below the party.
Due to how encounter math works, a creature of this level is counted as between 0 and 10 XP in the rules for building an encounter as its chances to hit are too low to matter against the player (-5 to hit against +5 to all defense at a minimum, often more from proficiency upgrades).
Of course, that’s for abilities targeting defenses, surely I just have to pick things that don’t target defenses or satisfy myself with spawning an annoying flanking/body blocking buddy? This is correct, some very select support-oriented monsters, like the Satyr or, in an undead campaign, the Deathless Acolyte can give an amazing boost for their level in a vacuum; but that’s before considering what truly seals this pan of the game for me
It’s woefully action intensive for the caster. A good way to see it is to say that you’re spending 3 actions to slow 1 yourself in order to add a level -5, stunned 1 monster on your side of the board, and if the support action of a Satyr might feel pretty good, is it really compared to other uses of 1 action for the caster, like using a composition cantrip, an appropriate metamagic, or using a well-chosen skill action like bon mot or demoralize? and that’s excluding the initial 3 action opportunity cost you could have spent on a more potent spell
In short, there is a reason why level -5 creatures don’t count in the encounter budget, and while a well-chosen one might impact the fight positively, 2 of its actions are almost never going to be better than 1 action of a creature 5 levels higher;
Of course, that doesn’t mean the spell is useless, out of combat in the blood lord adventure, for example, a single cast at 4th level of animate dead can be used by the Wizard to heal everyone for 20 + 3 x (2d8+16) to distribute on the most injured in a minute with a deathless acolyte; that’s amazing, and notably way more than the 0 a wizard would be able to provide otherwise. Similarly, if you know something is booby-trapped and you don’t want to risk your rogue, a Crawling Hand will happily eat and “disarm” it for the party for the cheap price of a 1st level spell.
Summoning was specifically defanged in combat, probably as a design concern about minion spam that was prevalent in previous editions, so just… don’t use it in combat and demoralize/bon mot every turn instead, you’ll be doing more good for your party
If what you’ve seen comes from r/pathfinder2e on Reddit, it’s likely because the place is a borderline echo chamber nowadays, and will happily swear that everything short of dumping your key stat is viable regardless of whether it actually is or not.
You’ll have a hard time finding any mention of something in the system being “not as good as the rest”, or, god forbid, the system having specific shortcomings (you might see “the game has shortcomings” but specific mentions will be absent).
I really invite you to check multiple posts and look intently for those less positive outlooks, you won’t find many and those you will find are likely to be at the bottom, on the other hand, you’ll see a ton of echoed opinions about the absolute superiority of pathfinder 2 math, game design, class balance, etc… either over other popular system or in absolute.
I don’t think the moderation team there is complicit, but it absolutely has let it go to shit over the years
TL;DR: to answer more specifically to “What is it that makes people really like summoning in general?” pf2e Redditors like everything about the system whether it’s good or not
I’ve definitely noticed that unrelenting positivity. Tbh I put that down largely to a defensiveness and a sort of inferiority complex against the 800-pound gorilla that is D&D. I’ve definitely faced the wrong side of that before, including but not limited to the response to my big bullet point review of the system from the POV of a 5e & 4e player who had only read the CRB.
But with summoning in particular, I’m fairly sure I’ve seen it presented not just as a viable option, but as a strong contender for the best strategy, so I put it down to something slightly different from the above.
beats me. Honestly, I’d say someone probably started saying it was amazing and then everyone started repeating it, but the argument of “look at this free flank” or “wow, such body block” are the only tangible ones I’ve ever seen coming from there, and the body block one is absolutely risible when Illusory Object exists and does a better job, without sustain, for one less action, and for a static 1st level slot instead of a max level one, the flank, on the other hand, is everything but free and likely not that good if the melees are positioning themselves correctly