Even in early runescape a single guy maxing fletching could cover the demand for magic bows for the next few weeks.

That's why high alchemy was added, which made sure skills like fletching weren't useless. Of course everything is tied to the high price because of that, which is effectively the upper limit of the profitability of wcing and fletching. Pretty much all skills are limited by that, and always were. The main difference is that PvM used to be in the same range of profitability, making most other skills viable for making cash.

High level PvM pretty much made all skills useless in that regard. Herbs are useful like you said, but the skill costs a ton to get to 99. Basically the only way to make money off herblore is by killing stuff to get them. You said skilling isn't profitable because the stuff you get isn't useful but the useful stuff is even less profitable. And that's because high level PvM is so much gp/h that you can skip skilling and just buy everything easily.

I'm not saying it's a good or bad thing, just saying that it used to be more balanced. It's just a slightly different direction they're headed with the game.