The opportunities to start businesses like that are shrinking every day, by design, by the way that search engines are supposed to work. There is more content produced every day, some of it very good, and there can only be one (1) first page of search results. Your doom is essentially guaranteed. I'm not saying it's impossible, I'm saying it's just not an innovative or forward-thinking field to get into. The only way this risk would not exist is if search engines were inherently corrupt and you had some reverse engineered way to rank at the top. That ship sailed 5+ years ago[1] when the top search engines switched to machine learning.

[1] Unless you're w3schools, for some reason.