There is no doubt that a feudal King exercised dictatorial powers.
That the word has become associated with negative connotations more-so than King is just an amusing aspect of History and the absolute abuse and turning the concept on it's head by the declaration of “dictator for life” (essentially a King in all but name: ‘King’ being “a word hateful to any Romans ear” after the Roman Kings).
The original “dictator” provision of the Roman Republic was quite preferable to a King. He was elected during an emergency to assume dictatorial powers and only for a year or until the emergency was over.
The ideal “dictator” was Cincinatus - and our founders greatly admired him - founding a society under his name - and our great city of Cincinnati is of course named for him.
There’s no confusion over it at all. It’s just how it happens. Kings get dictatorial power, and hand it down to their progeny. At least when they’re not figureheads. The occasional benevolent dictator is nice, but sadly they’re the exception, the exception that some people obsess on then start thinking monarchs are great. But the vast majority of human history shows there’s a big gap between the theory of monarchs and the reality. Kind of like communism, in a pure theory world it’s not such a bad idea, very efficient, very altruistic. In practice with real live humans though both monarchies and communism turn out to be very bad ideas.