Could definitely be a factor there! Admittedly I don't actually know much about cars—this was just something my dad taught me pretty young that stuck with me haha. But from what I understand, it can definitely cause longterm stress that contributes to issues over time

That's the best thing for the car haha! If you use the parking brake, your brakes are holding your car in place. If you don't, the transmission is holding it in place!