>Why does it matter if someone else makes money on something they copied?
When the copy competes with the original. The original required investment of effort and resources, the copy is near-zero effort.
This is the case for certain original content video channels, where their content is literally copied and monetized, competing for the same viral links and diverting traffic from the original.
But unfair competition is often legislated against.
Without copyright, competition would not be for the ability to create -it would be for the ability to distribute. The end result would be much the same as we have now - an oligopoly of distribution channels, only they'd pay the artists less, if anything.
The problem you mention is essentially that people with more money and business acumen (here: social media companies) will leverage said money/business acumen to make even more money (here: promoting videos and reaping virality-driven ad revenue). They will amplify their initial business advantage to outcompete those skilled in the subject-matter work. Under capitalism, it's as often considered a feature as it is a bug; which one it is in any particular case depends on how popular the people getting outcompeted are.
Hindsight is 20/20, but to me, copyright law looks a bit like an ass-backwards, cart-before-horse approach. It's the legal equivalent of "solving" SQL injection by adding a client-side validation that prevents users from entering ' and the word "DROP" in their form fields. All it does is inviting exploitation.
Instead of making ridiculous kludges that end up benefiting those they were meant to curtail, perhaps we need to figure out a proper solution.
When the copy competes with the original. The original required investment of effort and resources, the copy is near-zero effort.
This is the case for certain original content video channels, where their content is literally copied and monetized, competing for the same viral links and diverting traffic from the original.