I mean, you are paying someone else to do those things for you.

That's not exactly what's going on. I believe a more apt way to describe it would be paying somebody that has harmed animals. This may sound like a distinction without a difference, but I don't believe it is. Whether I buy pork at a grocery store or not, they aren't going to kill any fewer pigs because of it. It's not like the slaughterhouse is going to butcher exactly one less pig because I stopped buying meat. If I decide not to buy pork chop the next time I go to a store, either somebody else buys the pork, it's donated to a food bank right before expiry, or it's just thrown away. The pig is already dead, and the meat goes somewhere regardless.

Unless you're the type of person that eats meat every day, there is very little change you can make at an individual level. Of course, much like voting, change starts to happen once you get a lot of people to make that individual choice. Get 20 people to stop buying pork, and the store might order less. But at that point, I would argue it is far more of a societal issue. So while we are directly responsible for what happens to farm animals, I don't think it's at the level of us literally killing them ourselves.