Yes it is worth it. I made a setup with an e5 v3 CPU a few months back. The CPU was without a doubt the biggest bottleneck in my system even if it is an 8 core one. It might still be okay as long as multitasking is key, but it TANKS per-core performance.
Battlefield V ran atrosciously with around half the FPS until I turned off mitigations.
If you have an older system, there is no doubt its worth it. It could be the difference between usable and trash.