[jamager]

This is exactly correct.

With graded readers, thou, you can have good reading experiences with around 3k words (ofc depending on language, book, etc).

[AlchemistCamp]

The Oxford Bookworms collection has a 400 headword level that includes quite a few interesting ~45-50 page stories. Their 700 headword level is more interesting of course, but for popular like English or Spanish there are a lot of options even for very early stage learners.