But most people don't want Google to not exist. They derive significant value from it - from Google search, from Maps, from Gmail, whatever. I think that the access they have to my data has cost me basically zero, and I've gained a lot.

Had 23andme had access to my DNA, that might be worse in future. Although today there is not immediately a lot of downside, you can certainly imagine futures (maybe slightly dystopian ones) where that turns out to be pretty bad.