I think “nobody” is overstating it a bit. But certainly the majority of people don’t care enough.
A lot of people use the reasoning that they don’t need to adjust their livestyle to reduce the kinds of things you mentioned, because some other people are doing much worse. And there is some truth to that. It is definitely true that the decisions of a small number of people make a massively disproportionate impact on the problem. But it isn’t a helpful line of reasoning unless you’re intending to take steps to change those other people.