GP gave some good points about benevolent dictatorship.
Can you elaborate on why it wouldn't be "the best thing" in general?
And ideally weight that against all the other scenarios where it is.
That said, I think every western country could use a temporary (say, 6 months) switch to dictatorship, because I worry we won't deal with this effectively otherwise. I have no idea how to ensure such a dictatorship would be temporary, though.
The notion of handing Donald Trump the ability to rule by fiat, let alone other national leaders, is beyond rhetoric, it's not even contemplatable.
We need coordinated, responsible leadership. Most governments have all of the constitutional powers they need at this time.
The people elected Trump, so why not give him a dictatorship for 6 months? After all, it's within the President's power to declare martial law for times of emergency. It's the job of the voters to make sure they don't elect someone who can't be trusted with the awesome power available to that position. The same goes for any democratic country.
The powers of the Executive, Legislative and Judiciary exist to balance one another out especially in times of crises when some dictator could come along and declare himself ruler.
The people didn't vote for a Dictator, they voted for a President with very limited constitutional powers.
Politics, power, and hubris are inseparable.
Powers exist to benefit and protect themselves, even agencies with the 'best intent' fall into traps of self-delusion and aggrandizement.
We saw 100 revolutions in the last century, most of them 'in the name of the people' - and almost all of them failed and did mostly the opposite of that even if there were a 'few wins' here and there. Literacy and some kinds of healthcare increased dramatically in Cuba ... and yet ... we still have Castro Inc.'s totalitarian fist 50 years later.
The very authoritarianism of any regime which gives it the power to do something possibly good in the short term is exactly the thing that prevents it from adapting in the long term.
Also, authoritarianism tends to limit the scope of influence and authority to a smaller groups, which is not good for many things that require a lot of voices. Creative fields, research, even market economies have lots of actors.
If Hungary were willing to give 'temporary powers' to some person who was not Orban, for say 6 months, well then maybe they'd have something, but otherwise, this looks like a power grab Putin style.
Of course, we don't live in an ideal world.
Funny example: Heaven (the Christian version) will be an ideal dictatorship (for Christians) :)