Speak Text not available in some apps? Add it back? In many (if not, most) Mac apps that display or edit text, you can select text and have it spoken out loud, via a right-click or the Edit menu:

Some apps that you would expect to have this ability, don't… which is a pretty big accessibility issue for lots of folks (myself included). Is there any way to forcibly get this functionality into uncooperative apps?
Note: I am aware of the Accessibility setting that assigns a keyboard shortcut to speak text… but it doesn't always behave as you'd expect and sometimes reads text from the page that is not highlighted.
The easy answer is no.
The more complex answer, is that it usually depends on the accessibility of the app. If an app doesn’t use the proper accessibility labels and APIs, it won’t work properly with other assistive technologies like voiceover and speak screen. A classic example of this not working is in an image