It depends from where you stream and what you stream. As superbigwaff noted, no 2 providers "package" the same content the same way. As widermouthopen noted, it depends on the video and audio formats: SD, ED, HD, UHD, Frame Rates (24-120 fps)...as well as lo-res, mid-res or hi-res audio.
For 1 HD stream, as an example, YouTube requires 7 Mbps...Netflix 5 Mbps...and Discovery+ 4 Mbps. Roku isn't an accurate comparison because Roku just connects you to these different providers.
Negotiated speed at the times of streaming may also affect bandwidth. If your network is congested 1 day, the provider and your streamer may have negotiated a different format than the previous day.
