Advertising isn't inevitable, it's a thing that was invented, it became the dominant funding model on the web because it appears to have no cost to the user and it doesn't appear to interfere with the free and open access principles of the early web.
It actually has significant cost to users, we pay in time, privacy, experience, and security.
It's eroded the free and open web, spawned walled gardens whose only goal is to capture more of the user's time.