You need at least 0.8g / kilo (referring to 0.4g / pound) if you are doing nothing heavy, like walking to the office.
If you do moderate sports, you are hitting 1.0g / kilo immediately.
If you do some more extensive sports, like 3 - 4 days / week in gym, you jumü to 1.2 - 1.4g / kilo.
Bodybuilders are quite above :-))
Regarding the number of chicken breasts - scary for me, Im enough with a half one every second or third day.
There was a great movie about vegan & bodybuilding with known sports people: The Gamechangers - https://en.wikipedia.org/wiki/The_Game_Changers
therefore, multiplied by 2, though the numbers I showed are higher