Recently Google Docs has changed the way it renders documents to the browser. It now renders an image canvas instead of the actual document text. This means any extensions that need access to the document text no longer works, including Read Aloud.
As recommended by Google, we developed a Google Workspace addon that will provide text-to-speech function specifically for Google Docs. The addon is now available on the Google Workspace Marketplace.
Here is how to install and use the Read Aloud Google Workspace addon.