You’re misunderstanding my point. I’m not saying that you’ve suggested that, I’m saying that it’s possible. The separation of attributes is a sliding scale, you’re suggesting that we move it a little closer to that end (which is certainly valid! But, like I said, it’s a house rule) and all I’m trying to say if that you should acknowledge that it’s a scale.
At one end, you can have all attributes rolled into one. This is perfectly fine, and some games run really well using this method (I’m a huge fan of “All out of Bubblegum” for one shots). On the other end, you have individual stats for anything the character can do. This is more simulationist, and some players love that granularity. OL has planted its flag somewhere in the middle, Brian Feister decided that there was enough difference between knowing something and being able to work something out that they should be different Attributes, and most players of this system agree. He also decided that being persuasive, lying, and public speaking were different enough to split up Charisma. All in all, he wanted a bit more customisation for characters in this system. PCs in OL are perfectly allowed to know a lot but be dumb as bricks, or just the opposite.
You can shift the system a little more towards your own preference for your own games, but you can’t really argue with what the game does by default. That’s a little like going: “Why use a d20? A d12 gives you less variance and makes your ability more predictable”. Entirely valid, and you can always change that yourself, but also entirely a matter of opinion.
This is what OL decided to do, and it works for a lot of people. If it doesn’t work for you, then that’s what house rules are for (and it’s super easy for you to change yourself), but don’t try and tell everyone else that their fun is wrong.