if you start from the assumption that each of us has a finite amount of money we will give to charity and that - one way or another - we will give that amount,

if you start from the assumption that each of us has a finite amount of money we will give to charity and that - one way or another - we will give that amount, then giving to things like fun runs and fancy balls (https://leukemiaball.org/ https://leukemiaball.org/) makes no sense at all (the donation pie is fixed). If, however, these activities increase the pie of actual donations, then holding them makes sense, so long as the increase in the size of the giving pie is not exceeded by the expense of holding these activities.