unfortunately we found it isn't at the quality standard required to move forward (5ht in a rwo for different apps)

Could you please help me with this problem
my app : https://play.google.com/store/apps/details?id=elbasha01.aprivate.allaboutcryptocurrency
has been rejected for this reason
This item has a nice concept, but doesn’t feature the required functionality and features to be approved as a premium item. Consider expanding the feature set here.
It is the 4th or 5th app in the row to be rejected for similar reason
Could you please help or advice me. I am really disappointed