@dalz did a dive into that a few months back. I remember reading it and being impressed with the detail he went to. So, I dug it up, and that analysis is here:

@dalz/data-on-the-hbdstabilizer-performance-or-hbd-added-in-the-dhf-and-removed-from-circulation-sano5c

But to sum up the part you directly asked about:

As for the DHF goes, the stabilizer has added a total of 3.6M HBD in its budget. Some of it is from authors rewards as beneficiary.

I don't think the community alone could do this. Or would do this. Who would look at profit and voluntarily push it to the DHF for the good of everyone instead of just keeping it themselves? The stabilizer is our best option.