Heres examples from Relive streaming on youtube world of warships: test stream - YouTube and here is OBS streaming youtube world of warships: test stream - YouTube only difference is that OBS have this setting to change Keyframe interval seconds (from what youtube warned about while streaming with Relive), it was 4seconds by default and needed to be changed to 2seconds and it worked.
It shouldnt be hardware issue or actual bandwidth, cpu i7 2600, gpu xfx 390, 8gb 1600ram, ssd, 110m/25m bandwidth