RE: So... which one is better?

To get 100kcal of broccoli, you'd need to eat roughly 300g of it. This would amount to roughly 8.46g of protein, and 1.11g of fat.

https://en.wikipedia.org/wiki/Broccoli#Nutrition

Steak is rather difficult to quantify, since there are so many different types, grades, fat contents, etc. But for a lean inside skirt steak, to get 100kcal, you'd need to eat just over 50g, which would contain 13.4g of protein, and 5.1g of fat.

https://nutritiondata.self.com/facts/beef-products/3820/2

I'm not going to go in to micronutrients, but it's wrong to say that meat doesn't have any. That being said, the discussion shouldn't be about nutrition. Humans can easily thrive without meat. It should be about the sustainability and ethics of the meat industry.