Time Travel discovered

Agree. As C C points out, remaining in the same geographical position when time traveling is nothing more than a plot device.

A lot of good time travel fiction would be utterly ruined if they had to have a super-fast spaceship to make a long journey, just to advance the plot at the human level.

Or worse, a lot of good time travel fiction would be utterly ruined if the protagonists arrived 50 years in their own past - only to promptly expire, floating somewhere out in the deep interstellar medium.
Should you reverse time and GIVE yourself your time-machine, the machine would cease to work since it hasn't been invented yet. It would be too soon for the machine to work. It must be part of the same time-line. ☺
From TheFrogger Post 69
You cannot change the past, it has already happened. If I reversed time, my life would be the same as it is.
The above is based on belief in a deterministic universe

Prior to the early 20th century, mainstream science believed in deterministic laws.​

In principle it was considered possible to determine all past & future events from a precise knowledge of the current state of the universe.

No scientist believed that it was possible to collect the necessary data & due the required computations in fast enough to make accurate predications.

The universe actually obeys probabilistic laws.

If it were possible to restart the universe at some time in the past, subsequent events would not match the history as currently known to us.​