When did the international community stop caring about NiziU?

I don't think they ever started ?

NiziU was never that popular with I-fans.

People paid attention to their first few comebacks because they were Twice's little sister group and the first fully Japanese group to debut from a KPOP company.

After that, they stopped checking them out. Just like no one really talks about &Team or NCT Wish.

Now, NiziU's main audience is their own fans and somewhat the Japanese GP.