[zeidrich]

Because many people speak similarly. If a number of people who speak similarly can train it, it can learn how you will say words that you haven't even said to it yet if a number of other people already have.

Machine learning algorithms haven't changed that much since the 90s, what's changed is the amount of data we have access to, and the amount of data we can process.

When you're training it yourself the data is what's limited. The fact that we can process more data doesn't matter if we don't have access to more data because you can't speak any faster.

But if you have millions of people speaking to it, then we can take advantage of the fact that we can process so much more data.