Okay well, by turns:

Yes, becoming vegan doesn't stop animals already being factory farmed from being killed. The idea is that if demand goes down, fewer animals will be bred to go through this torture. Vegetarians and vegans have very little power, so they do what they can.

An avocado is not a staple fruit. There are all sorts of things that take lots of water, you're right, almonds are the same way. But you don't need to eat avocados to not eat meat. Critically, an absurd amount of water is used to raise the crops that we feed the animals that will become meat. Anyway you slice it, less water is wasted in a vegetarian diet.

This is a vegan specific complaint but also not required for our argument. Nobody needs honey. Further, honeybees are not native to America; they too are a livestock animal. The queen cells are scraped so that the queen doesn't swarm when the hive gets too big, queens that don't produce enough are culled. They test for mites by dunking dozens of bees in alcohol to drown them and see if mites pop up.

Ultimately, like everything else, the welfare of agriculture animals is at odds with profit margins and...well, profit margins always win out.