Culture is not a reason to justify harm or violence. Just because we've always done something doesn't mean we always should, otherwise anything that falls under the umbrella of culture can't be critiqued, like genital mutilation, or child brides.
Culture is important, but we can just as easily establish cultural practices that condemn violence and harm, rather than support them.
How about all the creatures that are killed by harvesting machines when wheat, corn, or soy is being harvested... I imagine probably the number of small creatures that are destroyed are probably on par with the number of crustacea harvested each year.
Sure, there are absolutely deaths there. But the problem though is that the majority of crops we grow are grown to feed the livestock.
So you’ll still minimize the number of crop deaths by going vegan.
Even if you believe that plants are just as sentient as animals (which some people have argued to me…) then going vegan still reduces that suffering the most.
Culture is important, but we can just as easily establish cultural practices that condemn violence and harm, rather than support them.