Fluff may be the wrong word for it, so let me try to explain my goals a bit better. When I talk about scaling, I mean scaling abilities in addition to scaling numbers. I don't ever want a situation where a player has to choose between walking on water / air, scaring a dozen soldiers, or having a slightly better chance of identifying stone masonry. The latter might be useful, but it's just a numbers boost instead of an ability boost / addition.
Knowledge skills also do things for the game that I just don't like - make the best sages in the world also high level. Same with crafters, performers, and professioners. The best people in their field aren't the people who spent years and decades perfecting their art, they are people who treated these things as secondary concerns while they were out slaying monsters and gaining levels. So eliminating them as a skill, as a thing that you have to spend points on and has a rank cap, means that they can be as high or low as you want.
There's reasons to limit something like climb based on level though. I don't think it's appropriate for level 1 characters to climb walls of force, for example, but I do think it's appropriate for that sort of thing to be available at some point and be reasonably reliable eventually as well. So while I'm perfectly happy with someone writing "great sage of X" on their sheet at level 1, I'm much less so with someone writing "great climber" on their sheet (unless they mean that in a very mundane sense).
This doesn't mean that people don't have knowledge, perform, or craft things anymore though. You can still take knowledge (nobility) or (planes), and so on, and you can do it at any level that you want. You can have both knowledge about things or skill with instruments independent of your level as well as character power limited by your level, you just don't spend the same character resources on them. That's what I meant above when I said I was working on something for them.