Windows: PowerToys Text Extractor
Install Microsoft PowerToys, press WinShiftT and drag over the text. It's copied to the clipboard; paste it into something that reads aloud, like Word's Read Aloud or Narrator. Two tools and a paste each time, but free and offline.
Windows: NVDA
The free NVDA screen reader can recognise the text in the current window with NVDAR. It reads the whole window, HUD numbers and all, which is a lot for a single dialogue box.
Mac: Live Text and Spoken Content
Take a screenshot with CmdShift4, open it, select the text (Live Text), then press OptionEsc after turning on Speak selection in Accessibility → Spoken Content.
All three work. The common complaint in r/disabledgamers and r/Dyslexia threads is the same: too many steps for something you do every few seconds in a game, and voices that tire you out over an evening.