A slightly different point of view is provided by Quentin Vandeweyer, of the U. of Chicago:
There is something odd in today’s money markets. T-bill and repo rates are
negatives and the Fed’s ON repo facility is close to half a
trillion in uptake. Why is that? Because there are not enough T-bills
In this view, the natural way for Money Market ...
"in general, why would anyone be willing to enter a reverse repo at 0%?"
There's a long explanation at the site Liquidity Matters in their piece "A Band-Aid Known as Reverse Repo", which you can find at https://fed.tips/sico4-1/.
I have no affiliation with the site, I simply found the article useful.