If time travel is going to exist in the future, we’re likely living in the best possible reality.

Our history has been shaped by events that ensure the best outcomes in the future. It’s likely that after time travel is invented, people from the future would go back in time to try and experiment with the outcomes of various incidents that have changed the history of mankind — regardless of whether they were negative or positive — and set forth the most ideal set of events that in turn benefit the future they are coming from.

Interestingly, I think Stephen Hawking was thinking along the lines of this theory when he did this https://vinepair.com/articles/stephen-hawking-time-travel-party/.

Does this mean that we, as a civilization, have the right to play with fate however we want? Are future time travelers a sort of insurance that stop us from destroying ourselves?

Or maybe, time travelers will never decide to come back and alter reality

Changing the events of the past may risk destroying the future. Time travelers could decide to lock themselves to their reality because any change they make in the past might set forth a butterfly effect detrimental to their existence. Maybe we actually don’t live in a perfect reality; time travelers are simply too scared to come back here because they fear unpredictability.

Maybe, time travelers could have computers powerful enough to calculate every possible outcome of an event that could happen in the future.

It’s quite logical that in the future, humans could have invented a computer so powerful that it can model the complexities of fate and human decision. The reason why we often feel like we’re living in a terrible reality is probably due to the fact that we’ve not even come close to seeing the worst. Maybe the things we consider tragedies, like the World Wars, could have been orchestrated simply to drive the industrial and technological revolution we know that ensued. The idea of the people from the future altering our reality is something to think about.