how come theres only 6 teams left and I still struggle to confidently say a team is good except for g2?
Coz they employ pros who are way past their prime and have already won a title so they don't have that extreme need to win more compared to let's say a new rookie in the scene.
OR
They have plenty of pros who never won anything but they realized they don't need to coz their paychecks are literally the highest in the entire scene plus they make good enough revenue from streaming.
This is prevalent with NA more so than SA since the latter actually gives more chances to newer faces than the former. Also SA understands that at some point their best talent will switch to some higher paying overseas team.
That's why SA is far more stable than NA.