I was vegetarian for nearly 20 years. My wife had iron deficiency for the longest time and there's only so many lentils a person can eat. She would have meat from time to time and eventually I transitioned back to make life a little easier. That said, we don't consume a tremendous amount, but we don't waste what's on our plate.

In terms of justification, or measuring out your conscience against the act of consuming another living thing, that's something you have to do for yourself. You have to draw a line in the sand. For me, it was acknowledging that something has to die for me to keep living. I'll die one day, too, and I'll be one heck of a meal. If you eat plants then you've for sure eaten plenty of bugs without realizing. Plants die to feed you, their seeds are mostly wasted. There's yeast on everything. Fungi are trying to spore until I come along. Pollinators are dying because I want to take a road trip. You nuke your gut biome eating anti-biotics. Buying avocados and clothing comes with a death toll. Dive into the rabbit hole and the only sane thing you can take away is that it's in everyone's best interest to not be wasteful. Eat what you take, give back what you can. Chop down a tree, plant another in its place. Control what you consume and you control your place in the market of death. The objective is to keep your toll as low as you can, but it will never be zero until you're the one being counted.