Yes because winning 4 tournaments of 16 is "so dominant", even excluding the b/c-tier events and the showmatches
Also SK won 42% of tournaments in 2017, not very dominant as well
NiP still dominated didn't they? It was their era, their time at the top.
Every era have two things in common, they dominated for more than a year and had more than 50% tournaments in that year. NiP had more than 85%, Fnatic had more than 55% and Astralis had more than 70%. SK? 25% in 2016 with only 4 tournament wins and 42% in 2017 with 8 tournament wins. There was no dominance. Therefore, there was no era.