Vegan here. Interesting question! I think you're going to get a different answer depending on the vegan you talk to. Personally, this is the definition of veganism I subscribe to:
"Veganism is a philosophy and way of living which seeks to exclude—as far as is possible and practicable—all forms of exploitation of, and cruelty to, animals for food, clothing or any other purpose; and by extension, promotes the development and use of animal-free alternatives for the benefit of animals, humans and the environment. In dietary terms it denotes the practice of dispensing with all products derived wholly or partly from animals."
By that definition, for me, it is not vegan. If the VFT has been grown by humans, and fed insects, then that is non-vegan, because there was a lot of animal suffering that went into growing that VFT. Furthermore, VFTs are not required for sustaining the human body, so the only reason to do this is for human pleasure or something.
Edit to add: if the VFT was found in nature, I probably still wouldn't consume it, because 1) I don't even know if VFTs are edible 2) if they are, I've got better food with me that probably caused less animal suffering, and are less morally ambiguous.
Not trying to sound pedantic or rude, by just generally curious; What about all the other microorganisms, bacteria,etc that are within any given plant you eat line up with this eh, philosophy? I know this may come across as a bit reductionist, but I guess when you see a lot of edge cases, it becomes a sword XD
Like, how would veganism feel about a person's immune system killing off other things? Do you avoid hand sanitizer? I guess the crux of my questions boil down to where the line is drawn. Does it only apply to non plant/fungi?
Those scenarios fall under the "as far as possible and practical" clause. Plants and fungi need insects to pollinate them, and microorganisms for nutrients. Veganism isn't a death-cult, so we have to eat something. Therefore, those insects and microorganisms are necessary.
Ditto for immune system and hand sanitizer. They are necessary parts of being human.
Another common one to ask about is animals killed in the process of farming, such as field mice that are caught in machinery. I also recognize those as necessary in the current system, but I do grow some of my own food as a small way to minimize those things, and I believe that if more people cared, we could eliminate that problem. But it's not something in my power, so I must classify it under the "as far as possible and practical" clause.
Another is animals that die as a result of roads. My answer to that one is /c/fuckcars
There's a few ways to interpret that and answer. The why some animals and not others is more of a cultural divide. To my knowledge I've never consumed dog meat. I hear it taste...ok. I personally wouldn't seek it out, and that's an interesting question in of itself. Would I decline it in a survival situation, no. Would I decline if offered to me while in another country or something? Not sure.
The odd side effect of farmed animals is insurance of their survival as a species. Now, I'm not anti vegan. I don't think it's a bad idea. I'm omnivorous. Could we do better, ya. I've helped with the family farm before, growing a variety of produce. I've also hunted before.
It would be nice to go back to a more primal way of eating. Having to work for the food beyond driving to a grocery store or having them delivered. Most of humanity has lost that connection to the land and life cycle.
I mean, reread the definition. Oddity specifically states that animals are the thing to avoid cruelty towards. Bacteria are not animals, therefore they don't matter under this definition.
There are some microscopic animals that exist, but they still don't really contradict the definition because of the "as far as is possible and practicable" clause. You can't really stop your immune system from working so it's a moot point. Hand sanitizer doesn't matter since tmk the actual microscopic animals like tardigrades or roundworms aren't really affected by it.