Do you know the history of B.League? Why B.League is being more successful than V.League? Basketball is less popular than volleyball in Japan. Why?
If basketball players are doing fine in Japan, volleyball players will be fine too.
In terms of success they are below J League, with Japan's baseball central and pacific leagues being the biggest in Japan.
After the women's basketball team's success at Tokyo Olympics they gained even more sponsors while JVA and VL lost sponsors. The only one in the women's division unaffected by the lack of sponsorship is Hisamitsu.