Is "adopting a native font stack" different in some way from simply not using web fonts and doing it the old-fashioned way instead?

Edit: Other than using the magic font names "-apple-system" and "BlinkMacSystemFont" it looks like it's just specifying the Windows, Android and Mac fonts in order. This is not going to use the native system font on other platforms or if the user happens to have Segoe UI installed on Android.