I like to think that time travel is real but we have issues...

Physicality..

1. with the earth, solar system, universe etc moving and expanding, we haven't yet done the right math to control positioning in time. Net result is anyone we think we've sent back ends up in an unuseful place in the vacuum of space and no way to communicate it. Anything that initially survived the trip dies of starvation or lack of oxygen

2. Sending a mass through time removes that energy in the present and injects it into the past or future. This immediately pulls the mass back to the present like a rubber band. Net result is that everything is constantly time traveling with relative time to each other but no way to move out of position permanently