There is a more interesting question which is "what suits best the particular project at hand?"
Let's consider having a presentation to be published online, together with explanations and comments.
The benefits of human voiceovers are quite clear. A good voiceover sounds better and has more expressivity.
The benefits of text-to-speech are maybe less self-evident. I list them here, and I'll look into each of them in more details in separate posts:
- updating the TTS voiceover for a presentation, is as easy as editing text
- easier to create multilingual versions
- TTS is always available, 24/7, and it works quickly.
- easier to use different voices and characters