Right. It's also the right and good thing to do and you should be commended for it. The two aren't mutually exclusive.

People who eat meat know it can be healthy and terrible for your diet. The same way any other foodstuff is. They also know you're killing animals, often in terrible conditions. If you go through life caring about everything that has ethical dilemmas though, you wouldn't be using microprocessors, any clothing that wasn't made and grown by yourself, etc. You DEFINITELY wouldn't be on the internet lol. The Good Place had a wonderful look on going through that moral extreme.

Even going the living healthier route, the bigger issue is ultra/processed foods.

Veganism equating boycotting the meat industry is great for your mental, but does a basically non-zero hit to their margins in actuality. People advocating, voting, and being vocal are what makes the small then large changes to shift the food industry paradigm to non-sentient meat options. The people smart enough to make real efforts into alternatives are doing so. Yeah, you want to participate too and feel like you're doing something, and you are, but let's not pretend it's not for your own mental benefit. Both through how you feel by advocating for animals that can't help themselves, and by not participating directly in something you don't like as well.