Most of the stories in the Bible didn’t actually happen, so taking them literally is pointless. I’ve heard some good and bad explanations on the story. Take it as a moral story, Abel according to the story is a good person and things go well for him, and for whatever reason it doesn’t go well for Cain and God warns Cain to master his sin and then he too will be accepted. Instead of emulating the ideal of Abel, he goes and kills the thing he should become. And there is a lot of depth in that, these stories have been written and rewritten over thousands of years, distilling ideas about the nature of man, about sin, murder, living together, civilization and conflicts etc.
The original language is very interesting because the names all have meanings, some of the words have double meanings and probably a lot of commentary on it has been lost, so our translations are relatively poor as we don’t get the context fully.
And I agree with some of the others here, since about the Victorian era, we in the West have quite literally been coddled when it comes to the realities of humans. Veganism/vegetarianism is a luxury, back then, everyone’s best would have to be meat in order to ‘sacrifice’, from that perspective, meat is very valuable. Some people translate it as being the result of agriculture, but the meaning of the words could also imply he just picked up some random fruit that had fallen off the tree, so minimal to no effort (the words literally translated mean he ‘gathered fruits from the earth’)
Even if you want to take ‘god’ out of it, it is rich in meaning, without putting ‘effort’ into things people aren’t going to accept your work, but you can’t then be jealous if your work doesn’t get accepted. The rest of the story of punishment and walking the earth unable to be killed/die etc, again, lots of ‘lore’ to go into and if you think about it, given this is one of the first stories, you can deduce from it why certain laws keep coming back in every civilization.