They use much time in opening because they havevto transfer the engine move on the chessboard. Shame.
Cheating
In real blitz chess people always play fast opening, because it's too difficult to find something new directly in the game. Here the first ten moves in my opponents take in average 1 minute in a five mijute game.
Almost all my opponents are cheating. It's very easy to show. For example in bullet they increase their time move after move, while my time goes down inesorably. Even if I move with premove. In blitz they use much time in opening, while everybody knows that you can't find something new in opening. In real chess I'm 1600 and I often win with 1800 and sometimes even 2000. Here I'm 1150. It is ridicolous and a shame for chess. There is also another problem: swindling. In real chess people who swindle are not well considered, while here all opponents swindle, continuing the game even with a rook less. It's pitiful. Sorry for my english.