Core i5-4590 is pretty long in the tooth these days, but at 1440p resolution, your graphics card is the bigger bottleneck.
I'm trying to wait until the 4th quarter of this year to upgrade my graphics card. We'll be getting new GPU generations from both suppliers. AMD will offer us their first ray-tracing GPUs (Navi 2x) and NVidia will offer us their first GPUs built on a modern EUV fabrication process (Ampere). Both should offer significant improvements over currently-available GPUs and drive down the high prices that NVidia has demanded for their current GeForce RTX20x0 (Turing) GPUs.
On the CPU front, AMD's current Ryzen 3000 series (Zen2 Matisse) processors are excellent. I wouldn't feel bad about building a new gaming PC on a B550 or
X570 motherboard today. Ryzen 9 3900XT's 24 threads would make short work of your video streaming. However, Ryzen 4000 (Zen3 Vermeer) CPUs are also due at the end of this year and should offer a slight performance boost.
The other drawback to building right now is that there are significant shortages of motherboards,
power supplies, etc., and some vendors have jacked their prices up by large margins.