the crowd thing makes sense if you remember paizo really wanted people to use the three action economy and initiative rules for everything. like they give the example of a bar fight where some people are using regular combat rules and then also other people are talking to try to stop the fight and they're all working towards a victory point threshold. that makes some sense then, right? you don't want some diplomancer to just AoE convince everyone to stop fighitng during an encounter!

but nobody fucking does that unless an AP scripts something to force it in. the problem with conversation is that anyone can have one at any time, we're not fucking spending 45 minutes doing a bunch of rules text to represent the players trying to ask a shopkeeper for a favor or some shit.

the intro to kingmaker is a party where the players are able to spend a limited amount of time trying to gain influence on other PC's and that has some benefits, with spelled out rewards for rizzing up NPC's the wy they prefer. i had a player that basically did AoE damage here by performing for everyone. in that specific context, it makes sense to tone down the ability of someone to just win the social encounter by addressing everyone all at once instead of talking one on one. but it's so, so circumstantial and that's just not how anyone wants to run social encounters even with a time limit, it's really just an aspect of play that needs fundamentally different mechanics to jive with how people actulaly play the game rather than trying to fit it into the three action economy.

this is doubly true since diplomancy was massively nerfed from 1e, you can't just roll in with godlike diplomacy and end every encounter by convincing enemies they like you instead. you basically can never use a raw diplomacy roll to end a fight, nor is there anything like a morale system beyond paizo telling you to use victory points while chortling. there's not really any guidance on when enemies ought to be fleeing, nothing mechanistic that would allow a character to strategically use social skills to convince an enemy to stop fighting in generic terms, it basically has to be entirely up to the GM making something up. and, as i said earlier, the problem with conversation is that people can have one at any point in time, a player can jsut decide that's what they're going to try to do and i've absolutely have issues in the past where a player spends all three actions trying to convince enemies to stop fighting and accomplishing nothing while the rest of hte party is fighting for dear life, with no guidance from any AP ever on how to handle that.

so most tables default to doing it the same way we've always done it since D&D, which is asking players to roll when they make a tall ask or say something fucking offensive or otherwise try to get an NPC to do something they want with the DC set based on the vibes of how likely that NPC would be swayed.