AI Speech to Voice Morphing

AI Speech to Voice Morphing is so much better at creating a believable speech pattern vs TTS however I notice there’s not a lot of information on it. There is one commercial solution. Here’s an example of what I’m talking about, https://m.youtube.com/watch?v=dNcTKEx-y8E

Any of you know how this is done or could point me to some open source projects? also What do you think about this vs TTS