I'd like to suggest as so many have before to add warehouse and backpack codes to dungeons, when players codes run out they get highly demotivated to play and not everyone can afford buying ap all the time.
With all that said, i maybe wrong but i believe that many people leave the game due to lack of being able to get space to put things which in return lowers the playerbase and prevents people from doing pretty much anything on a single character making people have to rely on multiple characters which really dulls character and class advancement in understanding more about that specific class for those who are free to play or can't afford the codes due to real life issues such as covid-19.