Depends on the game, graphics detail and frame rate you want to play at. Many games still won't be bottlenecking on the CPU side with an i3 at stock clock while a handful of the most compute-intensive games may still bottleneck on an i7, especially if chasing refresh rates beyond 100Hz.
Something always bottlenecks, the questions are which one will bottleneck the worst and whether you still care about it at the performance level where that happens.