It does not sound like the Arcade Fire. The Arcade Fire sound like British Sea Power.
To say it is unchallenging is to say that liek, Julian Cope is unchallenging because he was influenced by nice familiar garage rock.
It rocks out hard.
No Lucifer is the greatest song ever written.
They aren't being eccentric to make up for the lack of musical ideas. There are loads of musical ideas, and besides, the lyrics can't be divorced from the quality of the songs. The lyrics strongly make the song the high quality they are.
Fuck, they aren't even that eccentric. It's not like they're the only people in the country to be interested in light pollution, immigration and taking shit loads of drugs.