Humans have been concerned with monopolization and fair competition since at least Ancient Rome. Entire civilizations routinely revolt when the means of production and distribution are centralized to such an extent that both consumers and small businesses feel the pain.

Something rubs people the wrong way when Crassus became the richest man in the Roman world after buying up all the fire fighting companies, then using that to extort homeowners to sell at a deep discount when they were on fire. That was followed by many reforms that led to a public firefighters.

It was just over 100 years ago when the US went through its Trust Busting era breaking up the oil, steel, and rail. Ordinary people cared a lot about that. Enough to change the course of presidential elections.

Edit: Also, have you ever complained about how all the TV shows and movies these days seem to be the same? Just endless franchises and remakes and product placement and lowest common denominator slop? Well, a good part of that is due to media consolidation, which makes it harder for smaller independent TV and movie studios to compete. The soon-to-be four companies in America that control 80% of mass media are basically hedge funds.