Time travel is one that complex, hence the reason why many movies get to explore and portray it in different lights. It is mainly because it is something that has never been done, only hypothesized.
I agree with you that Hollywood does try to recycle the big stars in order to make more gains. This, however, has a big implication on the visibility of the upcoming actors. Therefore putting a lot of them outside the spotlight for too long. We kinda need fresh talent and faces.
Thank you for the tip, man. I really appreciate.