I have three routers, a drill press, tablesaw, scroll saw, lathe, jointer and most other power tools you'll find in a woodworking shop. I just don't use them much anymore except the lathe . I will buy a nice band saw, mostly for resawing.
For cutting grooves I use a plow plane.
For finishing flat surfaces, I use smoothing planes. I rarely sand. A planed surface shimmers under a clear finish as the wood fibers are sliced rather than abraded.
For curved surfaces I use draw knives, spoke shaves, carving chisels and scrapers.
For inlays, I use scratch stocks.
I can listen to music or the birds as I work and I don't have to wear a face mask or respirator or worry if I'll still have all my fingers when the day is done.
Hand tools won't replace power tools totally but they can add a great new experience to your work.
Instrument making will give me an excuse (like I need one ) to get some of those fantasic luthier tools like violin maker planes.