hi there
nice topic
short is easier - lets leave it here
there is so many things involved

• just content you like - "quality content"
  or
• analyze of user - post types, consistency in posting - topics, engagement in community, wallet activity - all these through of span of month, months and year ( users activity graph)
  maybe users should do this themselves and explain increases or decreases in activity and change in post types etc ( one of requests to be candidate for vote(s)) - summary of account

that would be filter for me - second one
second is long term imo but it is better building block

enjoy