Matchmaking?

I have noticed, as a last season plat player, i had hard time this season to get up to gold, but my friends from bronze and silver, who i know are terrible players got up to silver 1 really fast , in like 150 games or so, ok for me to get gold it took 30 games, but still, as i check what players they get against them, and what players i get against myself in silver 1. All of my opponents are plat in previous season with some g1 and g2, while their opponents are usually bronze 3-1, silver 5-3 from previous season. Thats what op.gg says. Is it intentional or what ?