This is similar to the principle of economies of scale in the real economy. To manage a fund, no matter its size, some necessary fixed costs must be invested, such as a fund with a scale of 1 billion and a fund with a scale of 10 billion.
A fixed cost of 100 million is invested, so the management fee for a small scale is 1/10, while for a large scale it is 1%. Even if other expenses other than fixed costs are added, the basic law of inverse proportion will not be changed.