Ability to custom purchase all craftable items
My biggest wish for the Sims 4 is to have an added game mechanic that allows Sims to purchase any craftable items from packs. We have the ability to make jewelry, clothes, candles, potions, art, etc. And while I enjoy the randomness of Plopsy, it would make so much more sense to have the ability to custom "order" any craftable item. You shouldn't have to master the gemology skill to buy an engagement ring or master nectar-making for a case of wine. And grabbing it off of the gallery just isn't as fun. Sims also make money so quickly, and this would be a great way to add another option to spend it while utilizing existing pack features. There could be a shipping upcharge, delayed delivery, and other familiar features of ordering online, all tied into the shopping app on the phone. It seems like a missed opportunity for the amount of craftable items that exist in the game now.
The inverse is that there should be a universal freelance career that allows Sims to take custom orders for craftable things and deliver them (ship them), similar to the mechanic for Plopsy, but mixed with odd jobs or the notification for video requests. It would be a small addition but could increase gameplay for SO many packs that produce items.