Okay, plausible, I guess. The problem boils (no pun intended) down to a problem of anthropocentric one; that is, it's impossible to ask a shrimp how much it hurts. Perhaps it hurts a lot or only hurts a little, or it varies based on other factors. It's not necessarily an unknowable, but it's an unknowable in human-relatable terms because (human) intelligence and theory of mind frame taking requires a prerequisite of linguistic understanding and compatibility. (Has not almost every conquering civilization deemed every indigenous group it encountered to be "dumb" or "subhuman" simply by not being able to converse? And, I'll take it one further that "intelligence" is purely a qualitative property inferred by performative interaction often respecting either strategy signals, complexity of response, or academic fashions... all requiring a shared language. This leaves out all other species because humans haven't yet evolved the intelligence or tools to communicate with other species.)
Also, why not endeavor to replace meat grown by slaughtering animals with other alternatives? The optimization of such would reduce the energy, costs, biothreats, and suffering that eating other living beings creates.
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