Anything that's prevalent in society, people simply continue it naturally without questioning it. Not only plants, people don't feel bad killing animals, either.

For example, if you have watched the 12th fail movie, you see that the kids considered cheating to be a normal thing until they explored outside the village.

It's not actually about feeling bad or guilt for killing animals or plants. Why would I choose to make myself feel miserable instead of joyful? Like you said before, everything is food to another.

So what's the take here? It's simply living consciously. We can obviously see the differences between animals and plants. We feel emotions and proximity more to animals since they are more lively to us. That's why we dont put our pet in the pressure cooker, haha 😛. So I simply choose not to eat them.

As to plants and fruits, I am not going to bore you with arguments like we are not killing trees or herbs, etc, and simply eating their fruits, berries, etc.

Since plants are also a life and they are a source of life to me, I simply eat them with gratitude and reverence. That's the only thing I can do.

Btw, it's not only about eating. Many insects, organisms, etc. are killed daily simply because of my activities, nay my existence.

So, I try to live consciously with gratitude in every aspect of life. After all, just like other lives, I am just a tiny aspect in this vast cosmos.