in undertale monsters even before the war were generationally convinced that they are weaker than humans and only magic turn-based combat can let them be on the same level. and they believed in that not knowing that IS what made them worse against humans
humans were mislead too, now thinking that the only combat style accepted for them is physical combat, which reinforces the "monsters are weaker" thing. of course they're gonna be fucking weak against a stab in the eye who isn't??? but nooo it's different when it's between humans.
if asgore and the entire underground wasn't convinced they're trapped by design, he wouldn't just be able to go to the surface and get the 7 souls, but he would've been able to do it with his sheer fucking muscle power send post
