UFOs are extratempestrials

Okay hear me out: Is there any solid evidence AGAINST this idea that UFOs could be future human time travelers? What evidence supports this idea?

I woke up in the middle of the night contemplating the universe (as one does), and this popped into my head. I know this is similar to the interdimensional UFO hypothesis (IUH), but I truly think that idea is less plausible for a number of reasons; Namely, inter-dimensional travel by definition implies a 4-D entity (humans) able to navigate in higher dimensions. Much like a stick figure drawn on a piece of paper logically cannot exist in a 3-D space, I don’t think humans can logically exist in higher dimensions than the space we occupy. Humans exist in 4 dimensions: 3 of space and 1 of TIME. So theoretically this should be possible right?! What am I overlooking!?