Who says they do the same thing? Did you read the link I posted?
That link is about skill synergies and advanced skills. If discussion about feats and rank benefits is buried somewhere in that thread I'm certainly not going to read all 5 pages of posts.
Under the current rules 3 ranks in Ranged Weapons-Pistol grants the quick draw rank benefit. Your suggestion is to make that rank benefit optional. I'm assuming it would cost skill points to purchase that ability, otherwise why in the world wouldn't someone take it? Suppose it costs 3 sp's, how is that different than a quick draw feat that accomplishes the same thing and costs the same 3sp's? Removing rank benefits from the skill section and creating a combined feat section that includes what is now split up among rank benefits, achievements, and perks is a far more organized approach and easier for the player.