Build for 3D Animation in Blender

I want to build a PC for 3D work in Blender. My current machine is quite old and is dropping frames in the viewport (animation playback), I have 5 fps.

I want to be able to animate some more complex characters and scenes without any issues with the animation playback so that I know that what I am seeing will be what will end up being rendered. According to my research, animation playback is a single-threaded task. Which means I don't need 64 cores, but rather 1 or 2 cores that are incredibly fast. Is this correct?

This is the build that I put together: https://uk.pcpartpicker.com/list/4PbP6B (note that I already have the 16GB RAM listed there, but if having 32GB is necessary then I will buy the extra 16GB)

For reference, here is my current build: https://uk.pcpartpicker.com/list/jNRmGk
As you can see it is quite old and upgrading RAM didn't help, I assume GPU is only used for rendering and I don't have issues with that, which leaves the CPU as the main bottleneck, unless I am missing something?