As much as we're hoping that somebody will finally invent time travel, there's one advantage to not being able to return to the past. Namely, we don't have to meet our past selves and explain all that's wrong with the future.
After all, if Marty McFly had a tough time convincing Doc Brown that Ronald Reagan was president in the '80s, they'd definitely think we were joking about the nonsense we have to deal with today.
And then once we started sobbing, they'd probably just think we were crazy. Either way, they wouldn't be convinced, and we'd never get them to help us prevent these problems of ours.