Chrome will be deprecating and removing support for the Theora video codec in desktop Chrome due to emerging security risks. The usage of Theora has fallen below measurable levels and it is often incorrectly preferred over more modern codecs. Theora has never been supported by Safari or Chrome on Android. However, an ogv.js polyfill is available for sites that still need Theora support. Support for Theora will be gradually turned down in upcoming versions of Chrome, with a tentative timeline for complete removal by February 2024. The removal of Theora support does not affect support for ogg containers.
https://groups.google.com/a/chromium.org/g/blink-dev/c/qqDdLkeyk7Y/m/ajHePzglAwAJ