One of the things I've noticed about Japanese home cooking vs restaurant style, in Japan - homestyle cooking is often pretty fucking unhealthy compared to good restaurant food, actually, especially in modern times with the advent of convenience and shortcut products.
Part of it, I want to say that because kitchens are so small and limited in equipment and size here, that it's hard to cook anything elaborate. Single-pan dishes are favored, and a lot of stoves only ever have 3 burners and a little broiler for a fish underneath. No range/oven combos here unless you're living fancy, and more likely they're still separate units. The ranges with 3 burners only fit like 3 tiny saucepans, too, or one big skillet and one small pan. Not much room to maneuver. My range only has 2 burners, no broiler, no oven. It fits one normal sized pot/skillet and a tiny egg frying pan, or two small things.
Also, there's just not a lot of variance or repertoire in Japanese cooking really, especially stuff people might want to try at home. You have your grilled fishes, you have nabe hotpots, there's nikujyaga, there's the perennial curry rice, there's hamburg steaks, maybe beef stew or pork stew in cream sauce, omurices, the various meat/fish cutlets, there's chinese stir-fried dishes, and Japanese-style stir-fried dishes, there's the rolled tamagoyaki omelettes, oden, etc - but most of these things are inevitably fried or not great food to begin with. A lot of them have convenience food starters and stuff too, Japanese people tend to be pretty thrifty about their at-home food costs, because going out is expensive.
I have this supermarket close to my house, and they sell pretty normal dry goods, plus nice produce and then amazing meat (owner is a trained butcher) - so there's A5 beef in tons of cuts and nothing else, Iberico pork, Bresse chicken or jidori chicken. Still, the rest of the food sold would pretty much only allow one to make the above dishes, not much else. There's a really controlled repertoire and if there's ever cookbooks or TV cooking shows, they're always railing on the same dish all the time. New stuff, I've never really seen.
Go out for good Japanese food though, you get a lot of stuff that isn't necessarily fried or stir-fried. It might be broiled over charcoal, boiled, steamed, but the feel is often light.