So one of the main issues I've had with 2E is the lack of verisimilitude in the skill system. (Everyone knows everything, anyone can fix anything, master basketweavers forge master katanas, but expert swordsmiths can't, etc.)
Now, I get that a bunch of people like the new system and don't care about "realism" and that's fine. But it looks like there's a very easy way to cater to both sides on this... and that's the already existing rarity system.
For those of us who value in-fiction realism, it turns out that the only two major issues with skills are:
1. Parceling out Craft and Perform to be more in line with Lore. (That way every musician can't play EVERY instrument, and not every stonemason and cobbler can use an alchemists lab to identify potions.)
and
2. Control which activities are available untrained.
Number one is an easy houserule. So if the book stays as it is, so be it. It's an easy fix for those of us who care.
Number two is actually an amazing way to tailor the game world to each individual campaign ... which is also the exact purpose of the rarity system!
For my game, I just edited the p143 skills summary table in Acrobat and moved the lines around to match the in-fiction particulars of my game world. For example, I have an urban monotheistic world. So I allow Religion and Society to have untrained Recall Knowledge checks. But not Nature. (And I moved Repair and a few others.)
It's a perfect fix for me, so I'm all good. But it just occurred to me that, if the devs just used the Rarity System colors on skill activities, it would highlight the ability for EVERYONE to bake in their own brand of realism.
1. Make untrained skill activities COMMON. ie. That's what MAKES then available untrained!
2. Make trained skill activities UNCOMMON. You can still use them, but you need to have an in-character reason that you can. (ie. You have the skill.) It's already the very definition of access to uncommon items!
Then, if you have a low magic world, like I do, you just make all the Arcane/Occult/etc untrained knowledge checks be uncommon (trained).
If you have high magic, maybe bump a few trained uses into common.
Same thing with all the others. Everyone gets to tailor their perfect setting. And all Paizo has to do is color code the skill activities to the rarity system!