Hmm, SBMM existed for weeks, yet people started complaining only when the devs admitted it officially. Just doesn't smell right to me. Anyway, if I'm looking at my stats, they're steadily going up in small increments since season 2. I had a few matches where there were like 1/3 diamonds and sometimes predators with almost 30k kills, but most of the times I just needed to land safe and let them kill each other, while having some really enjoyable battles at the end. Other times, the lobby is filled with beginners and the match is relaxed.
The only moment when my stats took a plunge was during Duos LTM, when there was a wave of sweats and cheaters. But nobody complained about having to work very hard there, hmmm...