Hey Jan, glad it made you think. As you've found out it's not easy to rank #1 on Google especially when so few people will link to your product reviews. You need to tackle a specific niche with a focused target audience as a whole and build a community of like minded people around your site in order to make any significant income online sustainably and for the long term.
Now you’ve got many different options to start earning online. If you saw something that really interests you, try it out and learn more about it. If you’re really wanting to make a full-time income online, you need to be dedicated to learning how to do what you want to do. There are tons of free resources out there. You just have to search for them!