This is a very important mindset. I grew up eating meat and I don't think I ever would have changed without realizing the fruitlessness of an all or nothing mindset. My wife grew up vegetarian and the past decade has been a slow walk towards me reducing my meat consumption gradually until now where I'm practically a vegetarian for environmental reasons. First I was eating vegetarian meats in our dinners. Then I started using it in my lunches I made for work. Then I started ordering it at restaurants when it was an option. Now I've been doing things like using oat milk instead of regular milk. It doesn't need to be 0 to 100. You can take baby steps and if everybody took even one baby step it would make a huge difference. Imagine if everyone ate even half the meat they do right now in the US. It wouldn't be perfect, but it would be better.