Or they already sent him back in time

I think the problem is that in an autocratic system, you cannot vote for change, so you must get change through other means. In the small scale, riots (as peaceful protest is often not allowed) will be cracked down on, but smart regimes often quietly make some of the changes motivating the rioters to prevent riots from happening again. Almost like voting.

Similarly, if people want regime change, they can’t just vote out their leaders, but have to start revolutions or coups. So autocrats rarely leave office alive