That’s not how this works.
So you can't name one either.
If you’re running an instance, it’s your responsibility to find an appropriate tool.
That's exactly what the admin here did, and what's more, he did so because he was forced to do so by a lack of "appropriate" or even adequate tools.
Hence the straightforward question you failed to answer.
I don't run an instance. CSAM is but one of the many reasons why. But I have been paying attention to the discussions regarding the flood of it here, and the impossibilities involved in starting from scratch with preventing/blocking this on a federated instance.
But for reasons I cannot begin to fathom, and with an intense interest in seeing this anti-CSAM tool remain unused, you are blithely sailing by all that with a demand for using a tool you personally could not even name and obviously does not exist in acceptable form, or it would already have been gladly implemented.
Glad he's ignoring you and carrying on. I think I'll do the same.
Name one. That exists and already works on Fediverse instances.