I most aircraft a co-pilot is not needed. However, most larger commercial passenger aircraft do require them. Airplanes require constant checks and re-checks of systems and checklists. A co-pilot...
If I were an employer, looking at your resume where it says "Private Pilot for so 'n' so for oh so long" I'd think, "This guy's got potential, and he seems to have a passion for flying."
It will...