Let’s imagine a world where time machines are invented.
Hypothetically, what’s stopping anyone from travelling to the past, where the dollar is much more valuable, and buying things at a much lower price? What if you then go back to the present, sell those things at a higher price and repeat the cycle? And wtf would happen if everyone there started doing that?
There would be machines which produce energy in any form where source is future.
Essentially infinite energy solution. So humans would essentially have infinite energy but if you are allowed to go anywhere in time then why would you stay i ln present. You would immigrate (for lack of better word) to a time when is most suitable and to your liking. You would die in 80 years why do you want to spend time in current world time if you can do better.
It would become like a multiple reality world where like minded people would come together in same reality and people who disagree with them go to their own echo chambers. I belive most people would be looking for fundamental human desires like food, comfort and sex so people will go to time where they get it most easily.