why are people so dumb? theories?

People have always been dumb. But now we are collectively smarter if only a little bit by way of natural selection. Smarter people being less likely to die by befriending bears or eating a scorpion then living on to breed.

So yeah, still dumb but not like the days of yore. Modern tech has made it easier for us to maintain knowledge out-of-brain which lends to surface idiocy. Also the lack of teaching history properly, truthfully, and thoroughly is leading to the 'ol bromide about repetition. So we've been on a low angle rise consistently for eons but our improved perspective makes it currently feel like a zigzag.

Because they rather think about their little person and be entertained watching a three hour movie instead of doing something that would actually help this fucking world that’s going to waste.

Why?

Oh and another factor may be that the gene pool has been negatively impacted by the advances in medicine and the rise in living standards.

In old times poor and by extrapolation less intelligent people didn't fare so well and suffered high infant mortality rates. Now they survive in much greater numbers and are rewarded with welfare payments for having a large number of children. And at the same time more intelligent people are having many fewer children. A double whammy.

People are less likely to make bad decisions when acting individually. However we do dumb things in large groups. Look up Dunning-Krueger effect and Group Think. We are social animals and that has shortcomings.

Chemtrails are real and there are tons of evidence to prove it. I don't even know what the argument is, evidence isn't hidden or covered up. Maybe people who say "chemtrails" say it in a shady, evil way ??? Who knows.

The far left has controlled the major universities in the Western world for decades.

MK Ultra

The Universe is flat.

Scooby Doo can talk... sort of.

I believe there are just to much media everywhere.

There are some impressive posts here. Yes! Stupid people bread like bunny rabbits. Smart people reproduce selectively, because we can. The head count between smart and stupid widens daily, with the stupid being ‘way out in front. Capitalist consumer culture panders to the stupid, although, ironically, I as a longtime salesman know that it’s much easier to make a sale—especially a good sale—to a smart customer than it is to an idiot.

What we have not touched on is (1) the USA’s deeply-ingrained disdain for intellectuals and intellectualism, and (2) the Industrial Design for public education in the US.

The goal of public education is produce a docile workforce for Capitalism. It has nothing at all to do with producing a population of critical thinkers and self-actualizing citizens. Its goal is docile and pliable workers, e.g., Amazon drones. The emblem of this kind of education is “the right answer.” The Industrial Model promulgates the myth that there is only ONE right answer to any question, a myth that nips critical thinking right in the bud.

Allied with this totalitarian approach to
alleged “education” (read: indoctrination) is the widespread bullying of smart kids. What do we call smart kids? Do we call them gifts, blessings, inspirations? No. Americans call them eggheads, four-eyes, nerds, geeks. Those are not compliments; so REALLY smart kinds learn to disguise their true nature. Gifted children who are not so insightful suffer and feel ashamed of their excellence. Being smart gets you kicked to the kerb.

US culture has always distrusted smart people, perhaps because we began as a nation of farmers. Farming is a physical occupation. Something like banking is purely mental. I imagine many farmers were I’ll-treated by unscrupulous bankers. There are obviously many other examples of this cultural tension between brawn and brains.

The irony is that high intellect and physical power can reside in the same body.

Because they prefer to enjoy life rather than constantly worry about how smart they come off.