Knights weren't just about gear though, they were the professional soldier class that spent huge portions of their day training in combat while the rest of society laboured and only trained a bit (longbows mongols were exceptions, they were peasant class who trained rigourosly with elite weapons).
Even if you take away the gear advantage it would be like spartans vs persian conscripts, legionnaires vs barbarian rabble, thin red line vs zulus/maharats or delta force vs some shitty african militia. Elite, disciplined soldiers have always had a HUGE advantage over a rabble no matter the gear.
That said the pre-1300 era was one where some gear and individual prowess went really far. After that time, new weapons and doctrines came into effect which limited the impact of elite knights vs peasants. Crossbows, then muskets were range knight killers that didn't require extensive training. The doctrines of oike phalanx formations and later tercios also empowered the the relatively untrained vs the elite.