A lot of these books were good. I loved meek, yet persistent Stuart Little. These books were good in part because the parents they were sold to had as a standard much older books, that had established themselves much more slowly, those by Louise May Alcott, James Fenimore Cooper, John Bunyan, and Shakespeare, and behind all these the Bible, of course. The farther you go back in the history of the English-speaking world the more the balance shifts towards the enduring and the eternal. You also travel away from illustrations to texts without illustration, which require you to use your imagination, much as radio did and TV never does.
Illustration does have a place.
I love the pictures by Lynd Ward for Robinson Crusoe. They have a richness for me that is, still today rivaled only by Rembrandt himself. When you are a child, the few things that are your windows on the world are decisive. They fill your mind. All later impressions have to crowd in, find a place among many impressions.