I use it almost exclusively/when it makes sense to. But so many people are surprised that I use it.
Part of it is because I was an android user until about 2015 and that was always a feature on the phones I had. I also use it because I have small hands and the biggest iPhone so I find it easier to type one-handed sometimes.
I use it always, even to comment here. But some times it predicts wrong and i have to go back and change it.