Part of the issue are professional style guides for written English, and they vary. The biggest ones off the top of my head are AP, Chicago, and MLA. I love the Oxford comma as shown in the last sentence, but in the AP guide they do not use it and it is wrong to use it for their style.

English is the best and worst language we have currently on the planet because it’s such an amalgamation and continuing to evolve and branch in ways that are hard to keep up with sometimes. It’s hard not to end up chugy don’t ya know.