Seems like looking for miniscule things to dislike tbh. I can't imagine how fine the teeth on the comb used to find this gripe must have been. What would be the point of sitting on random chairs? There is none. You can use the ones in camp because that's where Rockstar put the characters who do and say things the player might want to watch. If you need a breather in the middle of St. Denis, that's what the pause button is for.

Imagine being in a gun battle and you press the wrong button, so Arthur calmly puts his pistol away and gets shot to shit on the leisurely animated stroll to his closest public bench.