1080p 60FPS isn't difficult, you can easily do that with a Core i5 and in many games, a Core i3. That assumes you pair it with a capable GPU.
Now, if you're planning on a 1080p monitor with 144Hz refresh rate and want 144FPS that's when you can benefit from the i7-7700. If you're using a 60Hz 1080p monitor with no plans to upgrade, I would say that the gaming situation isn't enough to push you into Core i7 territory. Instead, put your money towards a good GPU like the GTX 1070 (for 1080p 60Hz, this should be good for at least several years).
If you do plan on going to 1440p or 4K or 1080p 144Hz then you can benefit from the Core i7. And if your budget allows for a Core i7 even after a powerful GPU, then you should also go for...