@NaturalTalentless
gaining an advantage in the early stages
Kind of the exact opposite. White starts with a slight advantage, because they get to make the first move. All the well-researched, most played openings are based on the premise that White tries to hold on to that slight advantage and potentially stretch it into an actual win as the game goes on and Black makes missteps.
What Magnus Carlsen often does is deviate from these extremely well-trodden lines and choose a move that isn't quite as well-researched, because what research there is has concluded that it just isn't quite as good - it allows Black to "equalize", reach a completely balanced position. It's usually not even an unknown move. It will be one that's in every book on the opening in question - but there's just a paragraph or two about, rather than ten pages. It will be far less thoroughly researched, and far less frequently played.
The reason he does this is because doing so effectively ends the "opening" stage of the game, which is usually advantageous to player who do a ton of opening analysis and have enormous opening knowledge, and forces the opponent to "play normally", as in, think about the position at hand and analyze it without the benefit of any previously obtained computer analysis.
Chess clocks only have limited time for each player, so the player who "thinks better" is more likely to win from an equal position with equal time. Magnus Carlsen essentially trusts that nobody "thinks better" than him - has higher natural ability - so he purposely gives up some of his potential advantage as White just to force his opponents to start thinking rather than playing moves from memory.
Arrogant? To think you're the best player in the world as long as nobody has the advantage of hours of hard work doing home-prepared analysis? You could call that arrogant, but he's the World Champion, so it's not like anyone's proven him wrong!