Thanks for pointing out ranking search results as a technology investment required; I tend to think of it as part of indexing but a good call out.

I purposely didn't want to go down the "quality" rat hole because that tends to devolve into subjective opinions (see DDG threads throughout HN). My personal, subjective opinion is that blind tests would likely reveal very little differences and thus justify their major investment in brand advertising made by Google.

(not blind but compare https://duckduckgo.com/?q=best+wallpaper with https://www.google.com/search?q=best+wallpaper; do you really want 3 pinterest results to this query; this is the burden of being the dominant search engine - you're the one people will game)

--edited for typos