Having active levies for a long time should bring disadvantages. This could help forts and the professional army balance

Ok so, right now, fortresses kinds suck. They eat a ton of money, and all they do if you have a smaller army is slow down invasions rather than actually stop them. So that got me thinking about how to make them good and role they actually played. And i realized that the [problems comes down to you being able to go to war forever. In real life, if you called up levies and sat them around a single fort for over a year, your nobles would get mad at you cause they have to be out here and their peasants are missing harvests, and the peasants want to see their family and also make sure their family doesn't starve cause they had to babysit a fort instead of grow crops.

Having a malus for long term levy deployment, weather that takes the form of pissed off nobles, damage to provinces levies were called from, peasant/levy revolts or a combination or something else could create a negative for long term wars. And thus, would make fortresses worthwhile, cause now making them babysit a fort for a year causes them to either make a peace deal with less leverage or tank growing maluses. It also helps give professional armies a purpose without making them super soldiers who win 50:1 against levies, cause having them babysit a fort doesnt have and negative effects, allow for larger and longer wars, giving states with professional armies a huge logistical/strategic advantage rather than a purely tactical advantage