emilyjh11 This laptop should handle Sims 4 very well. The graphics card can handle the game itself, all current packs included, on ultra graphics settings, with plenty of room to spare for your custom content or ReShade or whatever else you want to add.
However, you could do better for the same price:
https://www.overclockers.co.uk/asus-tuf-gaming-a15-nvidia-rtx-4060-16gb-15.6-144hz-amd-ryzen-5-7535h-gami-lap-asu-02778.html
This laptop has the same specs except for a significantly faster graphics card. While you don't need the upgrade to play Sims 4, it's worth considering if you want the best performance for your budget.
If you'd prefer to spend less, let me know how much less, and I'll have a look around. There's a significant drop-off in performance from an RTX 4060 to an RTX 3050, and I didn't see any other laptops with the in-between RTX 4050 and 16 GB RAM for less than £800. On the other hand, if you're willing to add extra memory yourself, this one is a good option:
https://www.overclockers.co.uk/asus-tuf-gaming-a15-nvidia-rtx-4050-8gb-15.6-fhd-amd-ryzen-5-7535hs-lapt-lap-asu-03776.html
RAM is cheap and simple to install on most gaming laptops.
As for desktops, they're typically slightly cheaper for the same category of components, but that doesn't factor in having to buy a monitor. On the other hand, they're much more upgradable and repairable, and the desktop version of a given component is more powerful than its laptop equivalent.
If you do want to look into desktops, please let me know how much you'd like to spend overall, and I'll see whether you can do better, including the monitor, than the laptop you found or the ones I linked.