You've got it completely wrong, before Disney took over Star Wars used to be a prestige brand. Now though, Star Wars is just one blockbuster among many, not even particularly good ones judging by the way that Solo bombed at the hands of an uncaring general audience. This is what brand damage looks like, showing how an initial success at the box office (like with TLJ) can make the underlying problems that same movie is causing. Star Wars is in decline across the board and it's all because of TLJ.
To that end, the same can well be true for Captain Marvel as well. It's a given that Captain Marvel would probably do well opening week, in only because of the good will the MCU has fostered up until this point. Unfortunately for Disney it looks like Captain Marvel is not going to replenish any of that good will; in this highly competitive entertainment market, with video streaming and a golden age of TV dramas, a mediocre Captain Marvel simply isn't good enough. It simply remains to be seen how the brand damage from Captain Marvel might be reflected in future sales. The week 2 drop is the immediate and most obvious measure. Although, a sharp fall in merchandise sales and underperforming phase 4 movies would be a more damning assessment of Captain Marvel.