At the end of the day, it's an estimate of throughput using test data which is often not representative of real-world performance because real-world data is much more diverse than speed test data. It's not meant to be a 100% technically perfect bit-by-bit analysis because that level of detail is irrelevant if you're in the ballpark for "good enough for streaming"
If you would like a speed test that hides fewer details and gives you a better idea of what you can expect for different file sizes, etc. try cloud flare's speed test
At the end of the day, it's an estimate of throughput using test data which is often not representative of real-world performance because real-world data is much more diverse than speed test data. It's not meant to be a 100% technically perfect bit-by-bit analysis because that level of detail is irrelevant if you're in the ballpark for "good enough for streaming"
If you would like a speed test that hides fewer details and gives you a better idea of what you can expect for different file sizes, etc. try cloud flare's speed test
speed.cloudflare.com