The only people who used it were people with senju and uchiha powers (Danzo and Obito).
Only obito has uchiha/senju powers and dna, so he has the full power of Inzanagi while Danzo's is incomplete.
Still, you need both uchiha and senju, no one else has used it without both.
It's a yin yang classification, you need the both powers to use a technique like that any way