Is SBMM working right?

My understanding is that if you perform well, you'll get matched up with better players and vice versa. I had 5 matches today. All of them were against Iridescent I killers with powerful add-ons. Each match didn't last long as some survivors died quickly or threw the games. Most of them were Iridescent ranks as well including me (Iridescent I). However, even if I performed poorly or died quickly, I was still matched with competent opponents. Shouldn't I be matched with less competent opponents when I perform poorly or die quickly. It seems like an endless try-hard hell now once you hit high ranks.