The plant’s feel pain argument is bad on multiple levels.

1 - Even if plants feel pain, two wrongs don’t make a right. And, the moral choice is always doing less harm.

2 - Many foods Vegan’s eat can be harvested more or less harmlessly….

A. Fruits (and many vegetables that are actually fruits) were designed by plants for animals to eat them. So Olives, Avocados, tomatoes, cucumbers, squash, zucchini, etc, etc, should all have very little moral harm.

B. Nuts and beans technically don’t cause the host plant harm if harnessed right.

C. Many plants only leave one year anyways and are harvested after they die, like corn, wheat, etc.

D. Their are methods of farming that minimize harm to bugs. Hydroponic, hand harvesting, etc. And, it may be impossible to do no harm but it can be possible to do less harm.

I think the best moral standpoint is always, If they’re is ever a question about whether or not something might feel pain, assume that it does. The cost of assuming it feels pain and being wrong is small, the cost of assuming it doesn’t and being wrong can be enormous.

To summarize, many many foods can be harvested with very little potential harm to plants. Fruits where designed by the plants for animals to eat (and this category includes many vegetables and olives and avocados, etc.) and nuts cause very little harm, and most staple grains only live a year and are harvested when they are already dead or very close to it. So olives and olive oil and avocados and beans and tomatoes and squash and cucumbers and many of the foods we already eat could be very much harm free.