The World Cup is now certainly an anomaly as it is discontinued since 2006, therefore, grossly unfair for those who come after as they will never be able to win a world cup. I strongly felt it ought to be replaced by something else that carries comparable weight as the other four stars, viz., Olympic gold, World Championship crown, Thomas/Uber Cup, Sudirman Cup.
My humble proposal is for the Asian Games, touted as the Asian Olympics, which is particularly relevant for badminton as the majority, almost 80% of the world's top players are in Asia, practically all the world's best in every discipline.
The next best choice may be the Superseries Finale at year end, my only grouse is it is limited to only the top 8 as per the SS Standings, as such the possibility of a worthy top contender being kept out due to unforeseen circumstances or personal reasons like injury layoff, taking a break after a major event, or even personal issues is not unlikely in any of the five disciplines.
Another consideration is, what if a player/pair suddenly breaks out to capture 4 or 5 SS titles in a row but somehow still fail to make the cut for not having the requisite ranking points to be ranked in the top 8 of the Standing List ? How we all wish to see such a player/pair included but owing to a technically has to be excluded. I know, that can happen to the WC or OG too, but I'm talking about the SSF as the 5th Star, since the two aforementioned of higher status are already included.
Besides, certain players or MAs may not care too much about the SSF as they might think most of their top players/pairs could be too tired to do well at year end and would rather take a break instead. Indeed, until now not many players/pairs regard the SSF as a highly prestigious event , not higher than any of the 5 PSS, and certainly not a major event.
On the other hand, I noticed the BWF in the new tournament structure next year has elevated the year-end SSF as a Grade 1 Level 1 event, that is higher than any of the existing Superseries, in terms of prize money and ranking points awarded. So it is possible, the future SSF may become a coveted title, hence one of the much sought-after accolade. Let's wait and see.