An analogy that I like to illustrate this is: going shopping for clothes vs going shopping for food. Both tend to have ethics attached to them, e.g. with child labor for production of clothing, and slaughtering of animals for production of food. If you walk into a store to buy new clothes, and there are 2 sections of the store, 1 for clothes that were produced using child labor, and 1 for clothes that weren't, and both sections had clothes of the same price and quality, the decision of which section to shop in is very logical. This is how I see going shopping for food- you have sections for food that were produced using factory farming, and sections for food that weren't. Both sources of food are the same price and quality. So the decision to make about which source of food to buy is, again, a logical one. It's also a decision that most people in the developed world have to make every week, at least people who live in cities and do their shopping at grocery stores.
While we unfortunately don't have visibility into whether our clothing is produced with child labor, many of us do know if our food comes from factory farms. In the US, the estimate is that over 95% of meat sold in grocery stores is factory-farmed. Why make the decision to buy that if you could easily avoid it?
But more unfortunately though, they're not the same price and quality. Whole Foods is called Whole Paycheck for a reason. I can get cheaper food from a different store that's good enough.
It is an interesting philosophical bit and it combines pretty standard modern morality with a pointed concept of not discriminating by species and instead trying to use the ability to suffer as when you decide if you should exploit something. In this paradigm the reasons not to rape or enslave people are the same as the reasons not to rape or enslave other animals.
This still has plenty of inconsistencies and weird bits, both theoretically and practically. Silly questions like eating braindead people stymie both sides until you get into the weeds about stuff like dignity. Would the theoretical cows in the hitchhikers guide that WANT to be eaten be ok to eat? Is it ok to have second hand animal products, especially if they are high quality and will prevent additional exploitation/consumption?
One of the most sticky conundrums I personally chew on is if this means we should actively try to prevent suffering, not just choose to personally try to avoid causing it. If the former, that means trying to make other people change their beliefs and behave in a way that is pretty objectively worse for them in society, which starts to edge toward causing suffering if you squint. It is easy to fall into trying to reason about which suffering is worse which is a terrible minefield where everybody loses. It's easy to SAY I value something no longer being tortured over my taste preference but is there a logical framework for that that can ever be objective and applied to harder problems? If it is only subjective then what makes it better than any other decision - people decide to eat pigs but not dogs every day but there is no more OR LESS reason behind that than the claim above. There might be answers but I haven't found them to be easy to pin down which is especially interesting because of how strongly I feel that not caring any hurting things is bad.
tl;dr being vegan sucks