If you could un-invent something, what would it be?

I have read a small amount of science fiction. Enough to know that tinkering with history is a tricksy thing in the hands of experts. I am clearly not an expert.

Un- inventing the Patriarchy and allowing women to flourish so that all societies had gender equilibrium from the get-go would be interesting.

6 million years of doing things differently. What would January 2024 look like ?