Well, considering it only spawns at y60+, it requires a completely different mining strategy that doesn't get me anything that I actually care about besides apatite, in areas I don't usually go to mine (hills and mountains), and the very fact that I COULD run out bugs me. The farms flat-out REQUIRE fertilizer to run. No other farming method does that. NONE. Every other one is content to let vanilla plants do what they want to, and most give you an OPTION to speed growth with a fertilizer. Forestry REQUIRES it and I haven't run actual side-by-side speed tests since the change to multifarms because I saw the tube requirements, size, automation requirements, fertilizer, and circuit board stuff and went "LAWLNOPE" moved to MFR and Steves Carts, and now Thaumcraft, Pneumaticraft, Blood Magic, computercraft, or one of the other half dozen or more mods that have farming mechanics. Because they ALL work without forcing me to go mine a hill somewhere for upkeep.
I do realize that a stack of fertilizer lasts like a month, or a week, or some rather ludicrous real-life time. That's not the point. The point is that if I'm automating something as basic and integral as a tree farm or wheat farm, or well... anything else. Speaking of, if it's not vanilla or extending vanilla? Forestry doesn't like it. One saving grace is that it's good with trees. It's one of the few mods that automatically handles Force Trees for instance without using an indiscriminate item collection method... which are most of them, so... yeah. Half point Forestry? Sorry for the tangent there, point is that if I'm automating a core system for basic resources such as wood or power? I don't want to have to maintain it. EVER. If I have to think about it for any reason, it was poorly designed in my eyes. There are systems where I tolerate, even like the maintenance aspect. There are ways around most of them. Even apatite... which involves either mining (and storing, or otherwise utilizing) a VAST amount more cobble, dirt, and coal (though there are other mods that do the above 60 thing... some exclusive even! Usually because a modpack author has done this themselves. Like some Metallurgy ores in ResonantRise), or voiding it. Which I do not like doing. Period. Call it a neurosis, call it OCD, call it whatever you like; I find the voiding of byproducts to be abhorrent. This includes Recyclers and AE Singularities, or any other mechanic that means "I get a bit of use out of voiding my X".
If Apatite was found at a reasonable level? I would grumble a bit and something else would be my biggest gripe... there are a lot of them I have about the change to forestry's farming. Heck the lack of the tight farm loops I used to do with peat bogs, autocrafting tables, arboretums, and... um... something else to create all the dirt, sand, ash/compost(mulch?) fertilizer, power, and such that I needed. That's a good system in my eyes. Give me the ability to make is self-sustaining and endless looping. THEN it's well designed. Because part of the reason I get into modded minecraft is so that I don't have to go chop down a forest when I want to build a mansion or a dock or a boat. I use mods to generally reduce things that I find tedious, explore new ways of doing things (occasionally), and then get into being creative somehow. Sometimes it's a pretty build. Sometimes it's a megaproject. Other times it might simply be a self-set engineering or gameplay challenge. But having to punch/chop trees or worry (Even slightly) about my apatite supply? These are annoyances and tediums that I simply do not want.
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The final bit of my response to YX33A touched on your exact problem. Try building big projects, or pretty projects, or doing things in a new way. "Progression" in MC tends to be pretty shallow, pretty easy to brute-force, and buried behind some form of time gate that if you get infinite resources, you can ignore. Mods like Rotarycraft (and even Gregtech) are much better about this, as are mods like Thaumcraft. But honestly? If you're playing tech mods to "hit end game" you're GOING to be either bored quickly, or get annoyed at the tedium required to NOT make it quick. Minecraft's biggest strengths are the procedurally generated "infinite" nature, and open-ended sandbox gameplay that lets you pretty much build whatever you want. You basically need to create your own challenges, or you're almost guaranteed to get horribly bored.