It uses 128b/132b encoding so 10Gb/s USB ≈ 9.69Gb/s you do then have USB framing overhead but it's probably around 2% on typical 1500B ethernet frames. So all in you are losing probably 5% or so to overhead.
I am of the opinion that 5Gbe is a much more sensible speed for a laptop adapter right now as it uses half the power and can obviously run full wack on 10Gb/s USB so you're looking at like 5Gbe vs ~9.4Gbe.
Stop insisting on Cat.6A (and related) copper cables for speeds beyond 1000BASE-T (maybe beyond 2.5G by now), just use dumb multi mode fiber it's way easier technology-wise and if you want power you can have that as well.
At distances where Cat.6A is even an option the demands on the fiber are very low. And it uses less power than the BASE-T PHY. The cable at least without integrated power is very thin as well, unless you can't respect it enough to not kink it, in which case you'd want a thicker one just to prevent you from being able to break the fiber.
In fact, just to for single mode fiber. Looking on fs.com, single mode cables are slightly cheaper, and the optics (for 10G) are $30 to MMF's $25.
And you get much better future proofing with SMF. And if you do need a long fast run, SMF is what you want.
5GBASE-T interfaces often use 3x less power than 10GBASE-T