One counterpoint against 1), and what eventually pushed me to stop eating meat, is the supposed humane slaughtering of the animals. It is not humane at all, and there is a lot of malpractice against the animals while they are in the slaughterhouse. There was a broadcast on Dutch television highlighting these issues. If your stomach can handle it; here is the link, but I warn it is very expressive:

https://www.youtube.com/watch?v=g2bwr7RotAs (~2m40 people reacting to what you will see; ~3m23 the actual footage)

To be sure, this is not some incident but some fundamental issue throughout the industry (at least in the Netherlands). There is only one big company responsible for most of the slaughtering. The government bodies supposed to be monitoring their practices had their budget cuts for years and now it turns out they can no longer do their job, and are said to be part of the problem. It is hard to give citations here because most of it is in Dutch, I am not sure about the situation in the US.

Slowly but surely there are more biological farms operating in the Netherlands, but still these animals are slaughtered at the same slaughterhouses the factory animals are slaughtered at. I am afraid there is no good story here.

Another counterpoint is; you are talking about cattle, but what about pigs and chicken for example? They are not happily grazing on some green meadow, but mostly always indoors (talking Netherlands here again), being overfed to grow as fast as possible, get as many piglets or produce as much meat in a as short amount of time as possible, then to be butchered in some awful way if they are unlucky. It takes very little effort to find mountains of footage of animals being mistreated on farms all over the world.

So I don't think the assumptions you make in 1) hold. There is no way to ensure that the meat you are eating (even biological meat), is from an animal that was treated respectfully during its lifetime and slaughtered in a humane way.

Ad 2), by the fatalistic argument, a whole lot of things no longer make sense (who would you vote, your vote does not matter). But consider the network effect you may have in your decision to no longer eat meat, and for example start making too long comments on HN to try to convince other people to stop eating meat. In case you can convince more than person during your lifetime to stop eating meat, habits and what is considered acceptable will shift eventually.