For once, I'm not limiting this to girl groups. Keep in mind that this is active groups, so BTS, for example, would not be included (Yes, we all know they're still the most popular group in the world--let's just get that out the way now).
BLACKPINK hasn't released new music in two years, and I see zero indication that we'll see new music from them in 2024, so that would make close to a three year hiatus. That's enough for me to consider them inactive.
This is actually kind of hard for my personal list. NewJeans is easy to figure out, but the other four are difficult.
I'll observe what other people's lists look like, for groups like Stray Kids, Seventeen, etc.
EDIT: Forget it. I've decided.
NewJeans
Twice
Seventeen