A fish's biology relates to the niche with which it sits. As such fish generally have small stomaches as they graze all day with the food passing through them at a constant rate. Thats why the small amounts multiple times a day thing is required. This changes once you have a predator which in the wild eats a lot of food at once before having to find more. So things like angels and tangs benefit from small multiple feedings/continuous foods (mature tank with algae for grazing). Predators such as lionfish and groupers only need to be fed intermittently as they catch a fish eat it and then have to start trying to catch the next fish, which can be days between meals. This is also the reason it is hard to get tangs fat in captivity as they graze ALL day. You can get them fat on fewer feedings of highly nutritious food eg pellets, but you have to be careful you don't make them obese as they will suffer from the exact same sort of systemic problems humans do eg liver/kidney failure, insulin insensitivity etc.
Having said all that I also love feeding my fish and mix it up regularly between frequent small amounts of pellets (highly nutritious) from an auto feeder 4x a day and frozen (significantly less nutritious with upward of 70% water in it) which I think also plays a role in their diet in regards to their digestion.