Not to splice hair, but Google isn't just "surviving", so the amount needed for DDG to survive is probably even smaller than that. They don't need to be as profitable as Google Search (which is much more profitable than the company as a whole) to do well.
Indeed, the part that they illustrated with Pong does show that in environments where you lose packets or have to reconnect there should be a more noticeable advantage.
It can be confusing to compare the mortality rate of cases in hospitals (which are be definition the worst cases) to the mortality rate of all infections (many of which never get to hospitals or get officially diagnosed). Gotta make sure we compare apples to apples.
I'd use the DDG iOS app if only the search field wasn't at the very top, out of reach in one-hand phone typing... It's terrible UX on anything but the smallest phones out there.
This is exactly what happened. Verizon probably didn't know that most of the traffic they were buying were because of adult content, and then they killed that. I wish they had sold it to Pornhub instead.