No it hasn’t been. Cockroaches, lobsters, and other arthropods have a decentralized nervous system. They have ganglia throughout their entire body instead of one centralized brain. These ganglia can react to stimuli independent of the other ones.
https://www.scientificamerican.com/article/fact-or-fiction-cockroach-can-live-without-head/
In this context “alive” means “still able to feel and process pain.”
You know, I’ve read that stabbing them through their head doesn’t really kill them because they have distributed ganglia instead of one centralized brain.
I would never trade the freedom I have now to be back in school as a kid who is beholden to the wills of adults around me.
I can’t tell you for sure which is quicker or more painless. I’m not a marine biologist and even if I were I don’t think I’d have the answer on another creature’s consciousness. Personally I think it’s really just cope and it’s splitting hairs at that point. You just need to face the fact that you’re killing and eating a living creature.