One important difference: salt-water animals (including crustaceans) harbor parasites which are less compatible with humans, for them humans are dead-end, they can't close the complex reproduction cycle. Land insects and fresh-water crustaceans (e.g. crayfish) are much more dangerous for humans. Lobster sashimi is much safer than eating a raw crayfish from a river or lake. The latter can cause a serious lungs disease.
> if you eat fresh produce from your garden, there are likely to come some small critters along with that.
I once found a caterpillar inside an eggplant ;)
Nice point. The flip side is that with land based insects the parasites can close the cycle with humans/mammals and hence insect consumption can be more risky.
(Parent comment) > if you eat fresh produce from your garden, there are likely to come some small critters along with that.
Eating food with the occasional insect that has gotten through (e.g in a vegetable or salad) will not be as risky as eating large amounts of insect mass. The probability of then getting a parasite or disease then will be much higher. Its just mathematics.
Why increase your risk probability?
this will always be the case. we can "survive" on a very safe diet
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Other freshwater fish like sturgeon are also served as sushi.
But then we ferment and rot lots of things intentionally and the products related to that are loved in some parts of the world and found disgusting in other parts of the world because they trigger the same reflexes as food that has gone off. E.g. a lot of Chinese people might not enjoy french cheeses and likewise the french might not appreciate some the fermented soybeans and eggs that are popular in China. And they eat snails, which with a lot of garlic and butter are actually not horrible but also not something everyone enjoys.
Anyway, if you eat fresh produce from your garden, there are likely to come some small critters along with that. Cleaning that is a percentage game. Likewise with organic produce you buy at the market. Small mites, spiders, etc. The occasional bigger bugs you might wash away. But a lot of smaller ones end up in your food. It's fine. We've evolved to be omnivores. Most of that meats with the acid in your stomach and gets broken down. Some of the parasites are a bit more nasty and actually can become an issue. Guess how those end up in your stomach. You eat/drink them.
Probably intensive farming of fish, ducks, chickens, or bugs does not result in the healthiest animals. Unhealthy animals get sick. Eating sick animals is risky. There are some signs that covid happened like that and there have been other examples of diseases spreading from animals to people via farmed animals traded in poultry markets or wherever.