It's always easier to simply state something is true than it is to prove it, or disprove it. That's a lot less of a problem when people aren't receptive to believing everything they see without question in the first place. Brandolini's law doesn't mean that it is impossible or undesirable to correct misinformation. It just says that spewing lies takes less effort. It demonstrates why it's important to give people critical thinking skills in the first place, so that you don't have to spend as much effort chasing and cleaning up after bullshit because that would mean fewer people are accepting it and forwarding it along.

The alternative being proposed here is to accept censorship which allows lies to go unchallenged entirely and makes it impossible to ever correct them.