I'm a fan. It's so refreshing to have all the HTML and CSS in your own codebase, under your control, instead of reading through a list of 50 sparsely-documented props only to realize that none of them quite do what you need.

Another example of this pattern is `downshift`, which is a headless autocomplete library: https://github.com/downshift-js/downshift

I would love to see a datepicker component that used this design. I have some choice words for the various datepicker libs I've used over my career and none of them are friendly.