Why was it uselessly slow from a USB 3 flash drive?

[Fiksdal]

For an Windows operating system boot drive, 4K random read speeds are the most important, followed by 4K random write speed, this is because there are a large number of small files in the Windows system.  The 4K read/write speeds of the common flash drives are always slow, so these drives are not suitable for creating W2G drive.
And the read/write speeds you said is sequential write read/write speed, not 4K random read/write speed, so it can't run Windows smoothly.

I see. I don't know what 4K read/write speed is, but anyway, I don't really need to know. Thanks for the answer.

This may be somewhat off topic, but is this only the case for Windows OS? Because when I run Linux off the same flash drive, there is no problem?