Well, not really end game, but why use diamond to double your ores,
Welp here we go. Why indeed?
when you can research for 10 minutes and get a pickaxe of the core
An exceptionally expensive item and unless you have an auto-book-enchant system or EnchantingPlus installed, very hard to make it last a long time. But yes, Pickaxes of the Core are amazing. It's a shame about the increasing costs of repair.
Addenda: And you do know the max yield with thaumcraft on nuggets is around 225%, right? So you will never reach the levels you can with Factorization or Gregtech. Indeed, native ore clusters preclude the use of any ore tripling process.
or just create a pulverizer
In current GT, macerators have a use again in automated processing lines. Their chief utility is in compactness; automated machines have big energy buffers and can feed power down their output face. This is actually a pretty amazing feature, and makes the competitive in many ways with the Pulverizer. But they are expensive to craft, and the iGrinder is prooobably where you want ores to go. It is true this machine could use a refresh.
The slag furnace output is not 200%. It also eats a huge sum of coal and is only really sustainable once you have a big mirror array set up with furnace heaters. It is pretty cool when you get a few surrounded by 3-5 furnace heaters in a grid tho.
And yes, I did play with gregtech. First time I blow a hole of 100x100 to bedrock with only tnt of a ragequit.
I dunno why. GT actually makes this way way way way
way cheaper. Every time you clear a tech tier your output and resources required drop. By the end of tier 2, you're producing at like 250-350% yield on ores and using 50% the resources. Gregtech also provides multiple ways to make infinite resources using the same infrastructure most people build anyways. It makes power generation easier, nuclear reactors easier, energy storage much easier (over time), remove processing centers easier to build. It also adds some pretty good automation tools. And if you have forestry and bees around, GT lets you make explosive sums of power with a bit of work there.
GT just really seems to be pushing you to automate and industrialize everything you can. If you don't like doing that, then you're gonna have a bad time. But Direwolf20's pack does the same thing with Forestry, so I suspect you're in for a trail of tears.