You are willfully evasive, so I'm going to take this as a sign not to waste any more time.

Perhaps some cultural phenomenon convinces people to start taking washing their hands after the bathroom very seriously, preventing tens of thousands of deaths every year.

It's a stupid example, but no tech would be needed. There's loads of problems in the worlds (wars, disease, famine, etc) that can be massively improved (progress) without any change in tech.