Used to cut all my dados by hand, bought a $130 router jig last fall and I feel like a fool
For about 9 years I cut every dado with a backsaw and a chisel, because that is how the old guy I worked under in Bakersfield taught me and he swore routers were for guys in a hurry. It took me close to an hour per cabinet side, and half the time my shoulder walls were a hair off and I would shim the shelf with a business card and hope the client never pulled it out. Last October I had a 12 drawer base to build for a kitchen in Fresno and I was already behind, so I broke down and got a router with a straight bit and an edge guide for $130. First pass took me 20 seconds and the shelf slid in dead flat, no shims, no card tricks. I finished that whole base in a weekend instead of two weeks. The dumb part is I still reach for the saw on face frames out of habit. So for the guys who cut dados by hand on purpose, is it the fit you like or the quiet? And has anyone got a jig setup that keeps a router from tearing out plywood, because that is my one gripe so far.
The old guy in Bakersfield was right and you gave up too easy. A router cuts one width, one depth, and the second the plywood is a hair undersized your shelf is rattling around. A hand cut dado you fit to the actual board, shim it with a card because plywood is never a true 3/4, and that shelf stays put for 30 years. The quiet is not the point either. It is that a backsaw and chisel never blow the shoulder out on oak veneer ply. Your tear out gripe is not a router problem, it is a router problem you signed up for. Slow down and score the line with a knife before you cut and half of that goes away.