Vanilla JavaScript is supported natively by all web browsers now. Nobody is suggesting using a 20mb framework to make a toggle switch work on a standalone page

Vanilla JavaScript is supported natively by all web browsers now. Nobody is suggesting using a 20mb framework to make a toggle switch work on a standalone page that isn’t a web app. If you’re building a web app either way, then choosing between a screen full of CSS or a handful of lines of js is negligible. For expanding sections, you should use native HTML elements when they do the job with less effort/code. You should use JS when they don’t.