Is it worth upgrading if there will be a bottleneck

[1neoisa]

I'm running an Athlon x4 860k and a Radeon R7 370 with 2gb and 8gb of ddr3 ram, I mostly play games on my pc and am finding that after running the gpu for 2-3 years my frames are getting lower and I can barely reach 1000MHz on my gpu with oc. I'm planning to upgrade my Cpu, mobo and ram next year but is it worth it to upgrade my gpu now to lets say an RX 580 that's on sale now and sit through the bottleneck until I upgrade the rest of my pc?

 

[hang-the-9]

I would wait, first, the current cards should be even cheaper if you want to buy an older one to save money, second, the same range models then will be faster if you get the next gen cards.