Affiliate marketing is not the only way to monetize your blog (or vlog or Instagram account).
If you have a standalone blog, then display advertising is an option. This means using Google AdSense or something similar to have ads (that may not be directly related to your content) shown on your site. With this type of advertising, you need a lot of traffic to earn a significant amount, so this isn't a great option if you're just starting or growing your blog.
Another popular option is selling digital content like guides, courses, and e-books. This is possible when you don't have a large audience, but a loyal niche audience. It's also a popular thing in some other segments, like those that create IT tutorials. Many travel bloggers have done this, too, though, with guides to things like travel hacking (and you'll find countless e-books on how to be a travel blogger). Of course, you again need a relatively large audience to earn a significant amount by selling digital content.
Guest posting used to be very popular, though it has fallen out of favor recently. Again, you'll need a rather large audience for anyone to offer payment to post on your blog (or on your social media).
Unlike most of the alternatives, affiliate marketing is a great way to start earning money even before you have a large audience (or lots of traffic).