Speeds are going to vary greatly.
Depending on the time of day, location, route between ISP and streaming service, provider’s connection, and which server(s).
All users can do is try to use the best connections possible.
One minute, you can get fast speeds, the next few minutes can slow down.
I remember way back in slow-speed days, I would complain to my ISP, and they would say do a trace route.
They would always say it’s not their issue, and once it goes off their connection onto another route, then it’s not their responsibility if it gets slow. And that was even doing speed tests.
And speed tests, most times, can be very deceiving, and every test I run always get my MAX download speed.
So most times when I don’t, then it’s something between the provider and my ISP or the provider itself.