On average, yes, but I think we're looking for unicorns given the prevailing North American commercial childcare model.
Huh. I can think of six daycares/preschools right here in my smallish town that meet the criteria I listed. Maybe I'm lucky in where I live, but I definitely think describing them as unicorns is exaggerating.
Assuming that parents can secure a space in one of those schools, it is an exaggeration where you live. It sounds like you are fortunate in your local selection.
That's not the case where I am-- a large urban center, where demand for quality childcare massively outstrips supply. Wait times here are about 2-3 years, on average. The Montessori that best matches the article's criteriasuggests applying during pregnancy, and even that doesn't guarantee a spot. Would I qualify that as searching for a unicorn? Certainly. But I take your point that my local experience may not be representative of the whole.