When I was a teenager, I used to play a video game called Red Alert. The context is almost this: Einstein killed Hitler...and Staline came in. @lunaticpandora's comment is actually very close to the game plot...
However, who knows what would happen if we remove Hitler. Maybe we will have a better history line, maybe a worse. There are too many variables that I actually do not know. To answer the post: we should not dream about changing the past... Let's only focus on making the future better.
I'm really not trying to change the past, and even if I would, I guess I couldn't 😁. On making the future better I believe what we do now is what actually shaping it. Thanks for your comment. I remember that name Red Alert but I don't think I played it.
We could not change it. Physics does not allow for it :D
We are indeed shaping the future in some way, at the present time... I am not super happy about what we do.. but well... that's another debate ;)
I'm not super happy either.