We've got 20Mbps fibre - started with 100, and realised we didn't come close to maxing it out, went to 40 & same story, so now on 20 & all is well.
2 teenagers watching Youtube or Red Bull TV or uploading video or online multi player games on the PS4.
Netflix as well, but then the PS4 is not active.
Have had no problems. That said, on Openserve the difference in cost between 20 & 40 is only R100 a month, so it's easy to adjust either way.