And in this case, they didn't work. Perhaps Qontour, as a web-native dev firm, has figured out a blind spot in Google's DMCA takedown process?

The blind spot is the same one that's always there. Takedown notices from partners are fast tracked, takedown notices from Joe Bob require a court filing.

(It makes some degree of sense - I shouldn't be able to use a burner identity to get Google to take down (even temporarily) a million-subscriber channel. The big problem with the DMCA is the impossibility of proving that a grey-area filer is acting in bad faith, but that's in the wheelhouse of the courts, not the platforms.)