Time travel is not for Avengers

Rating: 5/10 (27 April 2019)

One thing about time travel that no one seems to get.
The first Rule of time travel is:
You can not change anything in the past that lead to creating time travel in the first place.
Assuming that the Avengers didn't change any thing and the reason for creating the machine remaind the same
The big dramatic fight between the armies would not exist for 1 reason
if the Thanos and his team who came from the past died in the future after the 5 year mark the events that lead to creating the time machine disappear which means that they will not make the time machine and the whole branch will not happen
One more thing, where did the evil Army come from?
They were destroyed and scattered in the previous movie
Other than that every thing is perfect