I check my data every day, just crazy that way and notice that if I watch some streaming channels they use a lot more data, such as yesterday I watched Peacock and it used the same amount of data as last week when I had two tvs going on streaming with roku all day.
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.
Different streaming services may use different video codecs (encode / compress / uncompress / decode) depending on your streaming device's support for different codecs. The amount of data is directly related to the codec used.
