@Mateus_Montenegro
As always, adding cores and adding memory will help with multitasking. I would say in general that if you are running multiple multi-threaded applications, that you may be hitting the thread wall, as it were. The 7700k is a fantastically fast chip, but it only has 4 cores and 8 threads. A 7700k is going to be fast, but only has so many lanes, where as something like an i9 or Ryzen 7 is a little slower but can as much as double the possible lanes, and do more work as a result, though not necessarily faster work. In programs that can take advantage of it, you'll see a big performance boost, even with multiple programs running. People like to champion Ryzen 7 because you can game and stream on the same machine with little to no performance loss.
I don't think we will ever see benchmarks for this kind of thing. Even running Blender, Photoshop, and Cinebench at the same time would produce variable results that wouldn't give you more than just an idea of how it multitasks. However, in general, more cores will multitask more efficiently.
The Threadripper 1950X would be a good CPU that you would probably not max out with that workload. It might be more cost effective to look at the 1920X or the 1900X. Your workload would also benefit from the higher base clock speed and you might not actually need all the 32 threads... unless you plan on overclocking, then my suggestion flies out the window as the 1950X can reach the same speeds as the 1900X. However, don't count out the Ryzen 7 chips. Although they are mainstream they are still 8 core 16 thread chips. They could be the much less expensive solution if you find yourself maxing out that 7700K too often.