What data? We are talking about ads. It's not the crawling data which help in targeting, it's what people click on, it's what people read, it's what people do.
Being the search engine, if I search Asus computer, do you think it's the fact that there's Asus computer in the crawled content that will be used for targeting, or the fact that I searched Asus computer? When I click on the first link that say "Asus computer for cheap", do you think it's the existence of the page "Asus computer for cheap" that will help in targeting my ads, or the fact that I clicked on a page where it's about the value of Asus computers?
What matter isn't the content, it's knowing what each individual click and read. That data come from Google Analytic and Google Ads.
Why do you think Android exist? Why do you think Google Chrome exist, why do you think 8.8.8.8 exist. You are really mistaken if you believe they are for the good of customer (even though it's true they do bring some good), they are there to get that data and be the one that exclusively get that data.
If you want to compete with them, you'll need to beat Android, beat Chrome, beat their search engine, beat EVERYTHING that make Google what they are. Not saying it's not possible, but the cost of it make it nearly impossible.