Maybe if those were the only things you did. But if the bulk of your work is available at no cost, and no one is obligated to pay, then it's not a straightforward trade. It's not an exchange between equals. The power balance is all wrong.
If you're going to go through the trouble and expense of marketing yourself, why not actually sell something? It could be a $2.99 ebook or advertising space. But let it be something.
I never said that begging can't be lucrative. Still, it isn't the most dignified way to make money. It isn't the most scalable either.
We're experiencing a buggy-whip kind of paradigm shift. The line between amateur and professional is hopelessly muddied. And free content is the future of most forms of entertainment. It's not the best bargaining position but we have to find other ways to make it work. There may be room for everyone, but meals are not included.
We could use Kickstarter-style crowdfunding more often. Let the public pay us and then we deliver the work. We could even do it swarm-style, and form temporary studios to produce bigger projects.
Or we could take more control over the ads we host. The problem with automated ads is that they can be automatically blocked. Embedding the ad in the video or webcomic would involve doing our own market research and writing our own ad copy, but adblockers would be useless against it. We could even do it Thunderclap-style, and release the same ad across many different sites at once.