Yes, it would help. How much though depends from game to game. Originally I wanted to buy an i7 for the video, but they are stupidly expensive in my country (60-80€). So, I opted out of buying one.
Great video man! if you will upgrade to i7 4790, you can go with the GPU up to 2080 like i did! and then you will have a great gaming pc! the i7 4790 is way stronger then the i5. hope to see a video with the i7 :) i uploaded 2 videos with warzone 2 on i7 4790 and RTX 2080, and i'm playing 1080p on 60-70 fps, and 1440p on 50-60 fps.