A few advantages:
I will not drop a chain one time this year.
Not once (and this may be credited to the toucan-bill shaped chainkeeper, which is truly is genius, for the success or failure of a top-notch 1x10 rests with the quality of the chainkeeper) will my peace be destroyed by the sound of chain-rub from crank or frame flex. And I have many sweet spots, friends.
During group rides I will gain 10 feet on you every single time you switch rings.
And ten more feet while you realize you are now in too high or too low a gear.
The sweetest advantage of all: elimination of unnecessary thought.

Question:
What 2 vehicles in the world have TWO transmissions?
Answer:
Over-the-road trucks, and modern bicycles.

That is really all that need be said on the topic of front derailleurs.

Disadvantages:
mainly revolve around the staggering amount of work required to do it correctly. An insane amount of labor that went into this. Frankly, no one would, or even should, be willing to endure that.

Cassettes, chainrings, cranks, and bottom brackets are not made for 1x10, none of them. (Unless you want to go with a track crank and then spend 9 weeks on the internet trying to find a 3/32 144bcd). All have to be modified.

That is a very real disadvantage. And a big one. For that reason alone, I would not recommend a 1x10 to anyone. For the majority of the peoples of the world, it would be very, very bad idea.