Thank you for explaining! I did manage to find that Origin downloaded my DLCs to where Steam usually installs games a little while before your comment but I am still thankful for detailed answer. Also, where do you recommend getting my future DLCs? I really prefer sticking to one platform but it's kinda hard to do. Most of DLCs I own are on Origin (Seasons, Get Famous, Laundry Day Game Pack, Holiday Celebration Pack). I also own Cats & Dogs from Steam -34% offer for getting the game with that DLC and the following which I am not sure whether to count as actual DLCs of any sort: Awesome Animal Hats, Life of the Party, Up All Night
@MamusiaTheCat Animal Hats, Life of the Party, and Up All Night are part of the Digital Deluxe version of Sims 4. You can buy the DD upgrade in Origin, although it's usually cheaper to buy the DD version of the base game when it's on sale. The content is also not strictly necessary: it's just a few items that can be easily replaced.
Personally, I'd stick with Origin because I don't want my accounts linked, I don't want to have to run two game launchers at the same time, and there are fewer ways for things to go wrong. But to play only through Origin, you'd need to buy another copy of C&D, which is only $20 at its cheapest. On the other hand, you could wait for a better sale—you might well see one in a year or two when Sims 4—and buy other content from Origin in the interim. That way, you could switch to Origin-only when that sale came or when you got tired of dealing with Steam. Or you might find that the current setup works well enough for you and you don't need to do anything.
Sale prices are the same in Origin and Steam even if the sales don't always overlap. So if you see a new pack you want, you might need to be a bit patient, but you won't save money by purchasing through one platform over the other.
Saves can be transferred between types of installs without an issue as long as all required packs are present.
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