See I would have thought the opposite, guess labor management is way more important than I thought.
It's unironically not more important than you thought, it's just massively overvalued by this community to a point that I kinda consider comical
I disagree, though I have an unusual perspective on labor and the idea of the dwarf—most of my forts are less than 50 population.
Pre-rant, it's worth noting that yep, you absolutely can manage with just whatever the migrants have enabled or autolabor or whatever. Dwarf Fortress is not fundamentally a difficult "game", it's just unfair, hard to learn, and buggy—dwarves are just really productive little buggers, and often times the aforementioned bugs work out in your favor. If you really want, just spot weld labors onto a random dwarf whenever something's not getting done. Won't be pretty, but it'll work alright.
That being said, my main point is that managing labor yourself will not just change how your fortress runs for the better (which isn't as important; your lads can manage just fine as noted), but give you more flexibility and freedom to specialize your fort into whatever you really want to pour effort into and really have fun with the game instead of just surviving but with more dwarves.
I consider good labor management to be mostly two things: consolidation of jobs (have exactly as many dwarves as you need, no more, no less) to minimize the amount of dwarves you need to run the fort while maintaining productivity and sanity, and profession names to organize your workforce and make everything about maintaining your workforce easier to manage. Profession names sound trivial, but they help with sorting in Therapist, tell you what a dwarf's *actual* job is in combat reports and the unit menu, and let you rapidly reorganize and recruit for expanding workforce or military.
First, proper organization means more dwarf per dwarf. You get to make sure that only people who need to be on standby (or need to not go insane) are slacking off, and you get more FPS because you don't need to feed, clothe, room, and otherwise sustain 100+ dwarves just to run your fort and have a few squads.
Second, it'll improve the quality of your stuff. If you have too many masons, for example, you'll get garbage quality. But too few and you won't ever get the 100 cabinets+100 coffers order finished.
Third: in a crisis, you know who needs to get off their arse and do something. No need to give a new job to some random shmuck every time something isn't happening when you
know that Dastot does that job and you can just make sure he specifically drops everything to do it.
Fourth: having a system makes sorting new migrants into needed fields much easier because you'll know exactly what you're short on. Constant patch jobs of "crap, need another x, I think?" are pretty annoying when you have to search for somebody with a useless job and change it. And also make sure you actually need one and the existing ones aren't just slacking. Most migrants have fairly low skills in their original job, so you get a lot of freedom to scoot labors around as you see fit.
Fifth: it lets you do fun things, like caste forts, generation forts, or just regular small forts. A lot of mine are small enough that one dwarf per major labor will just not have enough dwarves to do everything, and I need leftover dwarves for soldiers and projects.
You'll learn what you want as you play more, and figure out what labors you can be patient with and use less dwarves on and which things you always seem to need done NOW and should dedicate somebody (or multiple somebodies) to. Or if you need things done NOW but only every once in a while, and can give that dwarf a second lower-priority job while they twiddle their thumbs waiting till they're needed.
But at the end of the day, I will concede that the bigger your fort, the less labor management matters practically speaking, and the harder it gets because you will have way too many dwarves to sort through unless you're proactive and keep things straight from the start.