I dont get the point. What do you want to say?
"Why Logitech AP work much better than MSFS default planes"
a) Logitech has no Autopilot, its an Hardware Supplier.
b) If you talk about the Logitech G Flight Panels, then again, its a piece of hardware, it is not an aircraft which could be compared to the MSFS default planes.
c) If you control the (MSFS default) aircrafts autopilot with the Logitech Panels, then why should it be working better with the Panel, compared to clicking the AP functions in the virtual cockpit? "Working better" means for me, you can do things, that wont work in the virtual cockpit. Or do you simply mean, its easier to handle? or easy to install?