Modem+router vs Modem router combo

Without the thought of QoS.... you always get a better connection in game if you're hard wired straight to the modem, rather than wired into the router, then the modem.

My question is if I bought a modem router combo, and I was hardwired into that, would I get the same result as being hardwired straight to a stand alone modem?

I mean I know I would be assigned local ip, but would it be optimal in the same aspect?

The router combo..not speaking in regards to isp provided combo.

I'm talking 3rd party like netgear nighthawk modem router combo