Why only 10 skills in the skill board?

POE2 got so many skill gems why only 10 skill slot in the skill board?
Even in the setting board it prepares 13 skill keyboard settings for the player but why only 10 skill slot in the skill board?? Actually only 8 available for players to BD because the first skill slot is default and can't be changed. And 1 of the slot will be the passive one. Thus only 8 active skills for players to use.. That's not good for players like me chasing mechanism in the combat.

Pleease do see my post and add more skill slot into the skill board