These hacks will just duplicate code by not using builting Explorer/Shell32 libraries and the like. So in the end you are running two instances of different tools. Also they will be totally useless on updates.

Back in the day you could use nLite and the like to replace W98's shell with the Windows 95 one, but keeping the compatibility. On GNU/Linux and BSD, you could use FVWM instead of bloated environments, or Fluxbox, IceWM... and still run things fast.

With current Windows tons of components are interleaved.