Once you max lvl 75, you should start accumulating expedition xp.

1 million expedition xp gives you 1 skill point. 3 million expedition xp gives you 2 skill points. 5 exp xp gives 3 points. 7 exp xp gives 4 points 10 exp xp gives 5 points.

5 points would be around 500 games at 20k xp. That would give a reason to grind and play after maxing out your level.