Did you have a question? (your original post didn't ask one until your edited… )
If you are commenting about the various speed tests that you find on the internet, then, yes, they mostly don't really show a true speed, but mostly just a guess, using various techniques. Since the last week of November, I have seen a huge variation in those tests (more than normal for my location) particularly in early evening my connection tests from 2 - 12 Mbps, all over the place, where in the morning it is fairly stable at my more normal 28-29 Mbps.
I predict my connection will settle down again about the last week of December.
Does that get close to your question?