Yeah, if you want something like 144FPS, you need to have an i7 for a lot of newer triple A titles, and even then that might not be enough, some games are too heavily CPU bound to get really high framerates but don't scale across lots of cores and threads and you will hit a CPU bottleneck no matter what CPU you have.
The 1070 is more of a 1440p 60 FPS card. If you are targeting 1080p 144FPS because you have a 144Hz monitor you're probably going to want to get a 6700k or 7700k.