@lily_wray330 A processor's speed certainly matters to Sims 4. But for practical purposes, you don't really need to worry about it. In your budget range, you can afford a good graphics card, and any of the good cards I listed (and other similar ones) will come with a processor that's more than strong enough, and runs at a high enough speed, for Sims 4.
In case you're curious though: Most processors will turbo when running a game anyway, so that's the number to consider. But the speed in GHz is not the only factor. The number of cores matters (more cores means more processes can be handled at the same time), and some CPUs are more efficient than others, so the speed doesn't tell anywhere near the whole story.
Anyway, for the graphics card, an Nvidia 1650 will run all Sims 4 packs together on ultra graphics settings with some room to spare. It may or may not run all current and future packs together on ultra, depending on how demanding those future packs turn out to be. It will probably be a close call either way. A 1650 ti is a bit faster than a regular 1650, and a 1660 ti is faster than that. In your budget range, you could get a 1660 ti, but probably not in a lightweight computer—it would be bulkier to accommodate the hardware, including the cooling necessary to protect the high-end components. Lighter, smaller components cost more money.
The MX-series graphics cards are slower than the 1650, but they also tend to come in the lightweight laptops I thought you were considering. A 1650 is over 200% faster than an MX350 and close to 300% faster than an MX250, at least in gaming. So in terms of performance, you'll do much better with a 1650 or above. But the MX-series would still run the game fine, just not on anything more than high settings at best. So the question is whether it's more important to get the best performance possible, or have a small portable laptop that runs the game well enough for your needs.
The Asus Zephyrus laptop is a good compromise, if you like the line. Otherwise, I can look around for other options with similar features. The first thing for you to do though is decide how much money you want to spend and for what kind of laptop: best performance, most portability, best combination, etc. Then I can list the best options I see, and you can pick whichever one appeals to you. Or, if you prefer, you can take the list of specs you'd want and shop around yourself, then link whatever you find for a second opinion. Either way works for me.