You've now interjected numbers in an otherwise word-only sentence, which is generally a no-no. You might as well just go for a bulleted list at that point sinc

You've now interjected numbers in an otherwise word-only sentence, which is generally a no-no. You might as well just go for a bulleted list at that point since you're breaking the grammatical flow. But there are plenty of other examples besides mine where the entire sentence meaning changes based on that comma. For example, "Amanda found herself in the Winnebago with her ex-boyfriend, an herbalist and a pet detective." As another point, for me the Oxford comma makes reading generally easier because it's clear where a list ends. If I see ", and" then I know what follows is the last item without having to read ahead and figure out if there's more to come.