TSM has to realize the fact that Bjergsen (and is the same for Doublelift) doesn't automatically have an advantage in lane they can snowball upon simply executing an average game upon that advantage and have to adjust to that thing
They built their super team upon the assumption that that their midlaner-ADC duo could always get ahead of enemy carry duo, given bot Bjergsen and Double were first in NA last season in CS and gold differential at 10 min, and esily snowball an advantage upon that
This is not true anymore with the influx of new players in NA, so they are getting outplayed since they haven't found yet their own peculiar alternative plan/style
And a lot of problems relies on coaching staff, imho, they have one of the weakest structures among the supposed "top teams" in Western scene , they basically have one LOL coach with previous success history (Jarge, and the success was in a different role as Deilor's analyst), and one analyst that has been for most of his career merely a remote analyst and a number guy, and I would argue he was with teams that weren't successful from a coaching point of view (volunteer as analyst for Alliance in 2014 being involved especially in pre-Worlds preparation, then working as analyst in for TSM from late 2014 going on), given that what on the paper is their Head Coach is bascially a motivator/lifecoach