FL residents can buy an Epcot After 4 Annual Pass. https://www.wdwmagic.com/other/florida-resident-epcot-after-4pm-annual-pass.htmi think this is an interesting idea but one that would likely never come to fruition for the reasons people are mentioning + they essentially have this already in disney springs + if people are already paying what they are asking to get into the park and potentially do exactly what you are suggesting, why charge them less to do it with more red tape? simply, "if it ain't broke (and it's already profitable), why fix it?"
that said, i would love to see an "after 4pm" (or whatever time) ticket. many times staying at the beach club it would be nice to walk into epcot and have dinner and stroll WS. there used to be (or maybe still is?) this option for people attending conventions at wdw.