Twice flopped because we had TOO much Twice over the years. JYP over worked those girls to the point they became not interesting to fans and they moved on to the next group.
Scarcity is what makes something more valuable, administration for dummies 101. The rarer something is, the more interest it brings and interest keeps companies rolling. Although, too much of scarcity can be a shot in the foot to kpop groups, cause' fans also get tired of waiting at some point and move on to the next group. But being available at all times is worse.
Twice may have past its prime, but imagine this: JYP deletes every single post on Twice's instagram. And then proceeds to schedule a all time low for the next month on the members agendas. And then, out of the blue, Jihyo attends an event that no one knew she would. Next week, JYP posts a teaser of 'what's new' in one of the official pages that isn't Twice's. It would get people talking and speculating so much, the tension is built and JYP could have Twice thriving again.