Do they agree on the recommended amount of protein that an athlete needs to begin with?
1g per lb of bodyweight is often bandied about, or sometimes lower figures like 0.8g per lb.
Especially while dieting, I’m rather unlikely to get to even that lower amount while just eating wholefoods without some supplementation in the form of whey powder. 30g of high quality protein from 100 calories of whey is absolutely impossible to beat with normal food, and being limited to chicken breasts, white fish, fat free yoghurt to get sufficient protein while losing some weight is rough.
On long days on the bike I’ll eat a lot more, but most of my calories will be pure carbs, with very little protein at all. I’m not going to squeeze my daily protein requirements into one meal when I’m home.