While the initial reasoning is respectable, veganism is t without it's flaws, several plants are not ethically sourced and either cause a lot of pollution, destroy habitats to be grown, or are grown via slavery, or a combo of all 3. The real issue is the systems that are in place across the food industry, plant and animal based.
Almonds are a big one that I know of. The vast majority of the world's almonds are grown in California, a state that has been facing severe drought for years now (though maybe not so much this year), but somehow still finds hundreds of billions of gallons of water yearly to keep almond farms irrigated.
And eating almonds is one thing, but processing them into milk is an order of magnitude more wasteful. It takes about 400 almonds to make a half gallon of almond milk, and each one of those almonds requires a gallon of water to produce. So that's 400 gallons of water spent to produce a half gallon of almond milk. A single almond tree can make about 30 gallons of almond milk per harvest, so we're looking at 24,000 gallons of water consumed per tree, which yields a full shelf of Almond Breeze at a single grocery store.
And as farms keep expanding and conditions become drier and drier over time, it's going to destroy the ecosystems of the state. And all so that people can have a decent milk alternative to have with their morning coffee and cereal.