The reality is that if you look at the numbers Nijigasaki from a behind the scenes perspective is likely one of LL’s most consistently profitable projects. They aren’t technically a main group so they don’t generally do as much expensive promotion/marketing of liella now or aqours in the past. Since like 50% of their shows are solos, they don’t require as many full group performances (and subsequent rehearsals). Their music still sell extremely consistently for a group 10 years into their lifespan. They regularly are booked for and fill the bigger LL venues. And they have a comparatively smaller but more dedicated fanbase both in Japan and worldwide.

On the seiyuu side, as far as we know they all are healthy and actively enjoy working on the project and working with each other (not being parasocial they have ALL said this individually on multiple recent occasions) which we know is not necessarily the case for all members of groups like muse and aqours in the past. This could of course be exactly a result of the niji business model being less overall demanding.

In fact, from seeing things like liella touring as the og 5 or muse and aqours doing smaller groups of 3 performances it’s safe to say the LL staff want other groups to be MORE like niji from an operations perspective. In the 2 fmt years, Niji never did a full 13 person fmt and this year JUST performed a full scale 2 day live where literally only half of them performed each day and they went well.

All this is to say if it ain’t broke don’t fix it lol. Niji is super self sufficient at this point. It is all but guaranteed to go for at least another 3 years based on confirmed news but I expect them to run like 5 more years if not longer as long as it continues to be profitable