There is this "Open UI" W3C effort which is supposed to be moving forward styling Select elements. Improved <select> is flagged in Chrome at the moment - it'll be great if this (and the other stuff in Open UI) actually get ratified into standards and ship. https://open-ui.org/components/selectlist/
I also wish we could style <select> lists. Like adding flags to <option> elements.
No mention of CSS page transitions or scroll-driven animations which can also remove some boilerplate JS.