Daisaku Ikeda and Soka Gakkai are unnecessary.

"Rely on the Law and not upon persons OTHER THAN THE BUDDHA." -- Nichiren

"In a scripture called the Nirvana Sutra, the Buddha says, “Rely on the Law and not upon persons.” Relying on the Law here means relying on the various sutras. Not relying upon persons means not relying on persons other than the Buddha, such as the bodhisattvas Universal Worthy and Manjushri or the various Buddhist teachers I have enumerated earlier.” (Repaying Debts of Gratitude)"

That means it  is worse than futile to rely on Daisaku Ikeda and the Soka Gakkai, failing to teach that we should rely on the Buddha as did Nichiren. Were they to teach what Nichiren taught, they would have to admit that Daisaku Ikeda and Soka Gakkai are unnecessary.