Absolutely this. I boarded at a barn with very big stalls - I’ve never seen so many stallwalkers, cribbers, woodchewers, and colics in my life. The stalls were dark with no windows, wood from floor to ceiling except the fronts. Minimal turnout, minimal hay.
My current boarding barn has pretty small stalls. Not a single cribber or stallwalker, and horses gladly come in and out during feed time. Some have to be lead back out because they’d rather stay in, LOL. Stalls are open and airy with the top half on all sides being grates so they can see and touch their neighbors. Plenty of turnout. Decent amount of hay, and boarders can supplement their own hay too if they want.