this take is a little bit too simplistic. There are use-cases where you are bound to a web-based framework but JS solutions are just not fast enough, e.g. data visualisations via jupyter notebooks. So you're stuck with some horribly slow solutions or non-interactive ones giving you pngs. Since you're plotting data, the text is minimal and the needed dialogs etc. are also minimal (clicking on a point and getting a label) or having a few options to rotate/turn on some features/zoom. And pngs with rendered text is as inaccessible as it gets, although data-visualisation may be fundamentally incompatible with accessibility tools since it is all about seeing stuff.

So I usually produce pngs via matplotlib and only selectively use interactive, js based, visualisations but they are get so unbelievable slow quickly when that your whole tab freezes.