That is a good point -- my simplification of the advance provided by JWST is aimed at saying, JWST is kind of the first major telescope with such depth and resolution to complement the deep fields of HST that everyone is so familiar with.

Herschel, while impressive also, was far-IR (if I recall) and much lower resolution, which was good for certain research areas, but less complementary to the HST deep fields for the, well, currently fashionable, recent study of galaxies at high redshift.