NOTE: This problem is solvable by display looking. The task can be reopened for consideration when https://github.com/WICG/display-locking/blob/master/README.md lands in a browser.
Due to sections being collapsed by default on mobile, in way that the browser doesn't consider as part of its searchable document index, most text in articles cannot be found by users via the "Find in Page" functionality of web browsers.
I noticed this during my teams' most recent offsite in Boston when we were doing some performance-related user testing, where a user found this surprising on their phone.
* [Find in page API spec (draft)](https://github.com/rakina/find-in-page-api/blob/master/explainer-extended.md).
* [WICG Discussion](https://discourse.wicg.io/t/allowing-browser-find-in-page-to-find-non-dom-text/1205).
* [W3C Discussion](https://github.com/w3ctag/design-reviews/issues/236).