Actually selection boxes are better for beginners. if you're a beginner, you don't have many cards and you are more likely to get cards you don't have and selection boxes have a mix of very good cards.
I disagree in them being better for beginners: the cards are so random and barely become usable once you get (except if they are staple cards)
I.e. You get charge of the light brigade what are you gonna use it for? Supposing lumina is in this box too you still need to buy judgement force to get raiden + buying more boxes for syncro cards