Adding a whole new branch of specialty that focuses on medicine. Starting with herbal remedies foraged in the different biomes (flowers, fungi, even bark of trees). Moving on to slightly more complex medicine, maybe some chemistry necessary in the laboratory. And finally reaching inoculation, nutrient supplementation, and antibiotics. Adding a branch of technology like this also open the door to adding different mechanics, although I had understood that damage per se is not something that devs want to add to the game, but maybe falling from height has a chance of breaking a bone, and now walking consumes more calories or makes you unable to add labor. You would need to go to one of this new specialist for a cast (a consumable), or a animal can bite you and you need a bandage, or you cut yourself while chopping down trees, or while cooking. You could even add that eating raw foods/lower tier food has a chance of causing a digestive infection, or you are randomly assigned to be allergic to certain food. Or regarding global event like natural catastrophes, a pandemic that requires certain resources to research, similar to how annexation works, for someone to find a cure/vaccine.
Idk, something I’ve thought during my 1.7k hours in the game. I think it would make the gameplay more interesting while also increasing realism