There's this tendency in more leftist and anti-authoritarian circles to imagine that the big corporations and the billionaires have a literally infinite pie of money and therefore they can fund all things for free.
And while they do have a lot of money, when you're scaling things to a general population, things get very very expensive. Facebook has to pay for a ton of infrastructure and bandwidth and hire a lot of very expensive employees. That has to be paid for somehow, and even Zuck himself wouldn't be able to cover it all for very long. In music, Spotify has never turned a profit. Movies cost massive amounts of money to produce and very often fail to make the budget back.
While it is true that one individual person blocking ads or pirating doesn't make a material difference, if everyone did that, we simply wouldn't have any of this stuff at all.
Tl;dr people need to read more Kant.