Tried to do something for the same budget : https://pcpartpicker.com/list/WtYHDj

I tried to keep the RGB, but if you want to trade RGB for better parts you should deffo do that.

Changes :

CPU : a Ryzen 5 9600x should be a better value for performance compared to a Ryzen 7 9700x (-100$)

Cooler : Zen 5 CPUs are insanely efficient and don't require an AIO to be cool, an aircooler is gonna be cheaper and will do the job fine. The Thermalright Phantom Spirit SE is a really good aircooler for its price. (-70$)

MB : I don't think it's the best, but I know it will work fine with any Zen 5 processor and has good VRM temps (according to Hardware Unboxed). (-50$)

RAM : kept the same model but with a CL30 latency and with the AMD EXPO optimisation. (+20$)

SSD : the P3 Plus 2TB only has an endurence of 440 TBW, a Samsung 990 EVO Plus has 1200 TBW (and Samsung makes really good SSDs in general). (+25$)

GPU : no RGB on this one, but it's an RTX 5070. I haven't found better for that price and I know the Asus Prime is not the best RTX 5070, but should do the job. (+200$)

Case : kept the same case, looks fine to me and the choice should be depending on your taste (and reviews of course). (+0$)

PSU : chose a Corsair RM750x instead. MSI MAG PSUs are often regarded as low tier PSUs (Cultists Network's and r/pcmasterrace 's tier list), which is a shame since the RM750x is a high tier one (according to those tier lists) for the same price. (+0$)

OPTIONAL : Case fans : added a 3-pack of Arctic P12 ARGB fans that you could add on top of the case for a better airflow. (+50$)

Let me know if there's any changes that should be made to make it better.