Don't think that 4000 is the maximum limit, because if you play in the fifth row, there will be additional activity rewards, that is, you can get 6000-7000 activity.
So if you really want to reach this level of activity, it is recommended to directly form a team with five rows for matching. In this case, the activity level will be increased more than if you were alone.
So if you want to brush faster, you can directly find five familiar friends in the association to grind together. This is more efficient and can break through the upper limit and upgrade your association faster.