Roman dictators weren't like modern autocrats. They were officials, appointed for a limited time (usually no more than 6 months) to address some specific emergency. They weren't crooks who staged coups. And it doesn't seem to have been a desirable appointment to hold; dictators often stood down before the time-limit.
I mean your technically correct that dictators were supposed to give up thier absolute power and indeed some did. But there is definitely a reason the term has adopted it current meaning.
Roman dictators weren't like modern autocrats. They were officials, appointed for a limited time (usually no more than 6 months) to address some specific emergency. They weren't crooks who staged coups. And it doesn't seem to have been a desirable appointment to hold; dictators often stood down before the time-limit.