https://www.gamespot.com/articles/red-dead-redemption-2-is-watching-your-personal-hy/1100-6462202/

For Red Dead Redemption 2, Rockstar Games is touting a more dynamic game world that pays close attention to your behaviour and reacts accordingly. However, it's not just monitoring whether you're being nice to the people around you and abstaining from robbing banks and holding up trains; it's also considering how you look and smell.

Being an outlaw is dirty work. All that robbing, killing, and generally getting up to no good gets the sweat glands pumping and wild west body funk going. And since it can be difficult for cowboys and outlaws to find some time for self-care, it's also easy to let your body hair get a bit out of hand. However, in Red Dead Redemption 2, it's important to ensure that Arthur Morgan is kept prim and proper. If you don't bathe regularly and shave, other members of the Van der Linde gang will call you out on it, even going so far as to take you to one side and stage an intervention. Characters in the world will also react to your poor personal hygiene, opting to give you a wide berth if you're stinking up the streets.