The iPhone X was better than the 6-8, I think the screen filling the whole thing helped it out, but it was still too large for my liking. I moved to the mini when it came out to get a smaller phone.
I found it interesting that the intro of the Duo talked about how it had 90% of the screen of the iPhone 18, as a way to talk up how big it is. They didn’t do this for the iPhone mini, and I think it’s why it failed. The iPhone mini screen was only .1” smaller than the 8 Plus, in a form factor that was smaller than the normal 8. I think selling it like that, as the base level iPhone (without the mini label) would have made it a success… but I’m still bitter they killed it off.