For the carcass a miter joint with Dominos is excellent as it hides the plywood edge. And it is really easy. Previously I always used the lock miter joint cut on the router table for plywood carcasses, but they are difficult to do perfectly.
The mitered domino is trivial. Use an angle gauge to set the saw blade to 45° and cut the miters. Then set the domino for minimum depth and 45° and cut for 5x30 dominos. They will just fit the 3/4" thickness. The joint will go together perfectly and will hold together for a dry fit.
As for the shelves, dados are simpler than cutting dominos in a flat surface. Get a straight cutter for the plywood thickness and rout the dados. Infinity Cutting Tools https://www.infinitytools.com/ Item 11-862 for 3/4" plywood. Perfect fit with no dado blade sizing aggravation.
You might consider 1/2" plywood for the shelves. Plenty strong and the thinner shelf looks better IMHO.