Counting through HLTV's big events tab.
MLG Columbus, ESL Pro League Season 3 Finals, ESL One Cologne 2016, IEM Sydney 2017, ECS Season 3 Finals, ESL One Cologne 2017, EPICENTER 2017, Blast Pro Series Copenhagen 2017, ESL Pro League Season 6 Finals.
That is 9 wins from Luminosity/SK from large tournaments.
IEM Katowice 2016, ECS Season 1 Finals, ESL One New York 2016, EPICENTERL Moscow, Eleague Season 2, ESL Pro League Season 4 finals, IEM Oakland 2016, ECS Season 2 Finals, Eleague Major 2017, Dreamhack Masters Las Vegas 2017, ESL PRo League Season 5 Finals, ESL One New York 2017, IEM Oakland 2017
These are all 2-4 placings from those events. Please back up your claims with facts. Na'Vi haven't won a major yet, they haven't won enough events and placed high enough yet, to claim themselves an era.