Is it possible that the native card reader is slower than the usb-c one ? Maybe a bus bandwidth issue ?

They both have the same goal of reperability and the same shortcoming (being way more pricy than competitors with the same performances). Buy one gets roasted and not the other.

Louis is the “same name” as Clovis. I mean by that it is how the name evolved as the dynasties changed their language from Frankish to Latin to then French.

Clovis was the first king unifying all Franks, so many Frank kings are named Clovis … and later ones are named Louis.