Technology

If anything this was worse under the old system. Making art previously costed a lot of money, you had to pay the artists for their time and money, and better artists cost more. So in the past that oil company could commission 100 top quality artists to make corporate propaganda while a person who cares for the environment but has no money could only make a drawing limited by their own personal technical artistic ability, which could be just stick figures.

This is why "high quality" consumerist and capitalist "art" and branding in the form of advertising is so abundant meanwhile anti-consumerist, anti-capitalist art is rarer, no one's paying to get it made.

Now any cause, regardless of money, can create at least mid art to get there message across. Those causes can also have way more people behind them then an oil company can reasonably hire

It's sort of like how the gun changed how power worked. Previously a king could use there resources to pay for a smaller army of well equipped highly trained knights to subjugate a group of people. Then when the gun came training and equipment didn't matter nearly as much and it became more of a numbers game, and to get those numbers rulers needed to give more power to the masses in order to be able to marshall them for their cause. Those rulers who didn't got overthrown in revolutions.