People have gotten stupider because the world is too complex (and fundamentally impossible) to understand in a completely rational way. Historically we have relied upon intuition, heuristics, and a network of trusted authority figures (usually a network of trusted institutions). The modern condition (post Enlightenment) can be understood as the elevation of rationality over all else and hostility towards heuristics a…
Is it possible that becoming an MD might require a base level of mental capabilities and hard work? Is it possible that becoming a Harvard professor in their Math or CS department requires a big helping of skill, work, and luck? Is it possible that passing the Bar exam requires, if not a genius intellect, at least a base level of intellectual capability? Is it possible that all these people you disparage are actually just normal humans doing a pretty decent job at playing a small productive role in running society?
More importantly: do you feel this way about the actual people that surround you -- your significant other, your in-laws, your old school friends, your coworkers, etc.? If so, please talk with a therapist (or your grandmother) about these feelings. This isn't meant in any way as an attack or belittlement. It's meant as genuine advice. Feeling like everyone around you is evil and stupid isn't healthy.