One of the realities of my sage abilities system is that while it gives additional abilities and skills to the players, letting them shape their characters more deeply and expanding greatly on the class structure as well, the most important thing is what the system does not give.
When 3rd Edition decided to create feats, they concentrated everything on a die roll that would make pass/fail the standard of the system . . . and because the feats were based on bonuses to that die roll, technically everyone could perform any feat, if they were lucky enough. A die roll meant that success was improved, not necessarily guaranteed. It also meant that not having a feat was not a crippling matter. We could jump the gorge, if we were pressed to do so and we might make it, no matter what we lacked on our character sheet.
It was an improvement over AD&D's approach to minor abilities, which was that everyone can do everything, almost equally. Strength might have some influence on our ability to leap and dexterity on our ability to walk a narrow ledge, but none of that had anything to do with class ability, race, shape, size, etcetera ~ and certainly nothing to do with player character munchkinism. Moreover, when it came to a skill that had nothing to directly to do with adventure, there was no limit whatsoever. Thieves and mages could walk through woods as easily as rangers and druids, everyone knew how to start a fire or build a tent, and certainly everyone could stand guard with equal ease or buy a donkey and of course handle it like a muleskinner. Why not?
By creating a set of abilities that meant a character could absolutely do something, without a die roll (make poison, identify the location of the party, make wine that could heal hit points, open a lock with a pick, sail a boat, forage, identify poisonous mushrooms, ad nauseum), it also meant that all those things would be something that characters absolutely could not do. Suddenly, a fighter can't teach someone else to fight, a mage can't just buy a dog and have it fight in combat, a ranger can't properly load a mule nor convince it to move forward as wanted and a character absolutely, without question, will drown if they try to swim.
This is a magnificent issue where it comes to player experience. They find a book and suddenly there is a chance that no one in the party knows how to read. There's a boat tied to the dock of the underground river and the orcs are hot on our heels, but does anyone in the party know how to keep us from smashing on the rocks? There's no fire started and there's no tinder either; who among us knows how to start a fire from scratch?
This stuff is limiting, annoyingly so. It is not the stuff "heroes" need to deal with. All our heroes can automatically do anything they want, since the storyteller conveniently covers them over with magic ability dust that permeates every crevice and crack of their upbringing. If necessary, we will invent a grandmother, an uncle, a neighbor down the street or what have you to teach the hero how to perform an appendectomy with a rock, a toothbrush and fifteen feet of twine. No problem.
But when the party aren't able to do that, and it is in their face from the start, watch them start to move together as a group. Suddenly, it isn't a question of liking the ranger because he has a lot of hit points; if the ranger dies here, the rest of us are going to starve to death in this wilderness because we wouldn't know the first thing about finding game.
It is unfair . . . but it is also marvelous. All the more because as the players acquire skills that no one else can do, it is suddenly no longer necessary to fight gods in order to feel like one.