i don't have any devices that require 40Gbit, so i can't speak to that. but in my experience, buying the cheapest cable off amazon will reliably give me 20gbit, and will charge all my devices at full speed (i don't know if it's PD2 or 3.0 or 3.1, but i do know that devices pull more power from my 100W charger than my 60W charger)

in practice, in my daily life, all USB C cables work the same. a couple years ago i got one bundled with a device that didn't support some feature, and so i put it in the garbage. problem solved. since then, all my cables work all the time in whatever device i plug them into.