Yes. It's worth it if you're doing a lot of things at once. Streaming, recording, watching vids, and browsing.
But if you're just going to game, then 8700K should be fine. the 15fps on online shooters that you will gain means nothing and it will all come down to skills.
Why run your car(CPU) at 9000rpm(clock-spd) for a slower acceleration and top speed when you can do it faster at 7000rpm. (with less gas)