But at least the lefty capitalist artist sold some key chains

Selling your shit and getting paid doesn't make you into a capitalist. At most you're an artisan, if you own your tools and you get paid for your final product rather than your labour hours.

To be a capitalist you necessarily need to own capital. In the example you picked you'd need to own a factory where you underpay people to and keep the surplus from all the keychains they produce.

And regardless of what you meant, you're absolutely barking at the wrong tree here, market consolidation and monopolies predate the internet, and they would have always had the final say in how we shape our infrastructure and share shit online under capitalism.