I use hand tools. I eschew the use of power tools at every turn, even for something as simple as drilling a pilot hole. I hate the dust. I hate the noise. I hate the danger. All of these things can be mitigated, of course, but I work wood to enjoy myself, not to be suited up like a diver on an extended deep sea expedition.
But I do what I do for a more profound reason than simple comfort. I do what I do because that is how it was done 250 years ago. In my hobby work (the things I make for me), I try to replicate 18th c. style pieces as closely as my skills allow. This means doing the work with the "proper" tools. I'm not judging power tools as "improper" in every case, but they are improper for the work I enjoy, where period accuracy is desired above all else.
18th. Century woodwork is full of what we would today term "flaws". Surfaces, even show surfaces, show tearout. Boards are thicknessed unevenly. Sometimes the marks from the saw pit or the tell-tale marks of riving are left untouched. Boards cup and tear out hinges because the original builder didn't take into account seasonal movement (at least to the extent we would consider necessary). Drawer runners get nailed on to case sides across the grain, what many would consider a major structural flaw.
It's more than just surface quality. Designing and building with hand tools, when properly done, yields a piece that looks handmade because of the overall composition of these "flaws" and design decisions based on the existing material specifications. You don't design a piece to an exact dimension, you make it work with the wood you have. You don't plane 7/8 down to 3/4, just because this is the dimension you see in the plan, you make 7/8 work.
This cannot be done with power tools, no matter if you have the latest Nurffurr 5000 variably-spaced dovetail jig. Those machine cut joints stand out like sore thumbs. So do router-made moldings. They are too perfect and look terrible on period work.
Since my goal is to make things look as much like the original as possible, I do not worry about the modern definition of "flaw". Sure, my surfaces sometimes show a little tearout, which usually goes away, visually, under shellac. My turnings are not identical and often show tool marks from my skew. My moldings show a little "movement" and are not identical from one foot to the next. My boards aren't perfectly flat (not hard to see why, my straightedge is Stick-of-Cherry, not Starrett). They are wavy, undulating, tactile, warm surfaces that show the pieces was made by hand, something that a machine cannot do. They are just flat enough to do what I need them to do. No more, no less.
That, my friends, is why I use hand tools. In no way should anything I ever say, anywhere, be taken to mean that I hate power tools, or that I somehow consider power tool work as less than hand tool work. It is just different. If my goal were different, I might very well put on the apron, safety glasses, hearing protection and fire up a Sawstop or a lunch-box planer.