This sort of dysfunction isn't new to history. China and Japan nearly industrialized several times in the second millennium, but such movements were quashed by the elites. Industrialization requires the ubiquity of fuels, machines, and at least low explosives; the last thing samurai who'd trained 20 years to be formidable with katanas wanted was to live in a world where a peasant with a hand cannon could be dangerous. The upper class knew it would better ensure its own survival by preventing progress, so they did.

Unfortunately, it seems to be an extreme historical anomaly for elites to put the welfare of their people over the zero-sum needs of their own class. One recent such anomaly was in the middle of the 20th century--The U.S. and USSR both invested heavily in building large middle classes (it being historically rare for such to exist at all) because they wanted research supremacy, which you can't get if you squander 95% of the natural intellectual talent, during the Cold War. Also, the existence of other systems put both sides on better behavior: capitalism couldn't be as scummy as it is today, and state-run socialism had to improve material circumstances and scale back the authoritarian tendencies it had developed during WW2... because, otherwise, neither system would have survived. But now that the Cold War is over, we're stuck in this global authoritarian capitalism that retains the worst aspects of both systems.

The division we're seeing is, of course, artificial. The elites deliberately pit people against each other (and trot out old divisive garbage: zero-sum nationalism, weird-ass conspiracy theories to distract from the more boring and often technically legal conspiracies occurring in plain sight, and of course antisemitism) because otherwise, the natural lay of the land would have 95+ percent of the people guillotining their dusty asses. That being said, I can't think of an easy way to end it. We do, as humans, need to (using your words) engage and unite; the problem is that what we need to unite to do--that is, overthrow the current global corporate elite using any means and mechanisms that shall work--is extremely socially unacceptable because those in charge have made it so. Thus, we're just expected to accept a declining standard of living and a nearly complete halt on technical progress at a time when we need it the most.