You can run a whole business by yourself, and accomplish a lot. You can make a real difference.
But when you build a team, you don’t just accomplish ‘a lot × the # of team members.’
You make a difference to the power of the # of team members.
In case you’ve forgotten that means not this:
Difference × 5
… but this:
Difference × 5 × 5 × 5 × 5 × 5.
(Hint: A team is not the same as a group of people in an office.)