let's say RS gold adds a fresh ore from Rskingdom's blog

To say most abilities are useless in runescape is only a legitimate statement if you anticipate there to be no upgrades to Runescape ever again. For example, let's say RS gold adds a fresh ore which requires 95 mining to collect, and it is 10x more valuable than the usual runite ore. If you just had 85 mining because runite ore rather than leveled past it, you would have to spend a loooong time to get that 95 mining requirement to mine the ore that is new, so long in actuality, that the costs of the new ore will probably have spiked significantly by the time you reach 95 mining. Meanwhile, all of the players with 95+ mining will be setting the costs for the brand new ore, and will have made millions if not billions of Gold from the time you get 95 mining and the costs fall. Yes, it is beneficial to train beyond the grade of gatherables/craftables.

You twisting everybody's points around and are beating round the bush. Like how you mention items being high crashing because that's how it is. This was my point, and also the fact I never mentioned smithing. They included the thing and amethyst happened I mentioned. Players with 92 mining created a killing and players that didn't possess it didn't sell it by the time that they obtained 92 mining to get its summit price. Because the precise situation happened in sport already so you is immaterial. Then you bring up alchmate if 75% of the osrs players use it.

That was precisely my point about high alching, you are never going to find an item with good margins that lasts for over 24 hrs since players will constantly buy out the supply until the prices are no more profitable, because high alching pushes the market for items that would normally be useless and prevents them from bottoming out just like a dead stock would in real life. High alching provides an artificial need to seemingly useless things thus keeping old content related and creating the rs economy as a whole lot different and diverse compared to other mmos, where most mmos are buy old school runescape gold gear treadmills where items will gradually become worthless and completely irrelevant in time because of power creep and the industry inflation which follows.