Games run faster on SteamOS than Windows 11, Ars testing finds

Might be unfair to call Proton a "translation layer" because the Win32 API is not defined in terms of system calls but rather a set of functions exported from a DLL.

Proton supplies a DLL that implements the Win32 API using Linux syscalls. Windows supplies a DLL that implements that Win32 API using Windows syscalls that you're not really supposed to use directly.