"Nobody would choose this life unless if they had to."
You mean nobody would choose the half nomadic hunters life?
Hm, some indigenous cultures I spoke to disagree, but the choice is not there anymore, as the bison herds they sustained on got slaughtered. The conflict of the nomads vs sedentary is an old one and the establishment of the latter, made the old ways of life simply impossible.
You're completely missing my point. Without any external pressure, multiple peoples concluded that settling and eating grass was preferable to being nomads. Yes, this includes the ancestors of the bison hunting plains tribes. It was only with the population collapse due to smallpox and introduction of horses where the nomadic way of life became dominant again.
Until the invention of firearms, nomads had equal footing with settled people, if not an advantage (e.g. Attila the Hun, Genghis Khan). The main advantage that agricultural civilizations had was population size.