This was brought up in #7909 (comment):

Unrelated, but such a missed opportunity to use shape as a parameter here. That would allow creating array with different lengths in each dimension.

Instead of the current signature which is

skimage.data.binary_blobs(length=512, blob_size_fraction=0.1, n_dim=2, volume_fraction=0.5, rng=None)

and forces each dimension to have the same size.