Tradeskills are a rabbit hole of evil. You get to a certain point in the 20s where you start needing stuff from other professions that can't be found on a vendor or farmed, so its either pay exorbitant amounts on the market, or level that other stuff up yourself. And then, hell, you need iron or elm or cotton or something, so you are also trying to level a gathering skill to avoid the market prices.
Before you know it, 3 days have gone by, you haven't killed a single thing, you are an expert leatherworker, culinarian and miner when all you wanted was to be a carpenter, you have callouses on your hands from endless node whacking, your leve allowance is at zero and all your gil is gone from porting all over the place.