A massive amount of Bach’s music and manuscript survived because his musical estate was divided and meticulously safeguarded by his musically trained sons—especially Carl Philipp Emanuel Bach.
his musical estate was divided among his sons. C.P.E. Bach, in particular, meticulously cataloged, preserved, and performed his father’s works, ensuring they survived long enough for Felix Mendelssohn to spark the “Bach Revival” in 1829.
SepiaGlyphs, Quora https://www.quora.com/Were-there-any-notable-benefits-for-musicians-like-Bach-to-have-so-many-children-especially-in-terms-of-legacy-and-musical-influence
Listen to his Violin Partita No. 3 and feel how modern soloist reinterpret and give the writing life: