I'd also like to add, that a lot of it depends on the applications you are using or plan to use for editing stills and/or video.
I think that is a point worth stressing. Different applications benefit from different components. There is a trend towards really high core counts with the most recent AMD CPU releases, for example, which yields dramatic improvement for software that makes use of these - but for other applications, spending money on these may be a total waste as they actually cost a lot and perform similar or worse than CPUs with lower core counts and higher clocks in some.
Assuming Photoshop and Lightroom are your tools of choice, I would recommend having a look at this site that has benchmarks for current hardware tailored around those applications :
Photoshop Benchmark
The core takeaways are these in my eyes:
"Adobe has been making improvements in order to make more effective use of higher core count CPUs, but for now, having beyond ~8 cores is typically not going to give you any higher performance."
"Although Adobe is constantly expanding GPU acceleration support to Photoshop, the current demand on the video card is actually relatively light. Even an entry video card will be able to provide a huge boost in performance for GPU accelerated effects but there is a sharp drop in performance benefit by using anything more than a mid-range video card."
"The exact amount (of memory) you need will depend on exactly what you are doing, but based on your document size we recommend a minimum of 16GB of RAM for 500MB documents or smaller, 32GB for 500MB-1GB, and 64GB+ for even larger documents."
I'll upgrade my PC soon too, likely with an AMD Ryzen 7 3700X, a Samsung 970 Plus 1 TB as a new main drive and probably 32 GB memory. For the board I haven't looked into it enough yet, so I haven't decided between 470X or 570X, this will require some more research as I plan to experiment a bit with GPU passthrough and virtual machines and that does not work well with all boards. This will be paired with my existing case, BeQuiet Dark Power PSU and Nvidia GTX 1070 and a bunch of different drives I already have in use.
That will be a system that is used mainly for editing with Lightroom and Photoshop, with some applications like Sequator, Deep Sky Stacker and Autostakkert getting some irregular use, as well as some gaming (too little nowadays).