Look it’s the greatest reality show ever. Sometime in the future we invent time travel and we send drones back to look at stuff. People have found them and decided, “hey, this obviously works let’s ‘invent’ it.”
So of course they cover it up, they don’t want competition, for the idea they stole, from the future.
Just assume time travel is possible, what makes more sense, traveling back to our own planet or some other super advanced civilization inventing FTL, finding us, and giving a shit to buzz around and mess with us?
Who doesn’t want a sweet 21st century photo to post on future Instagram!