But they’re not maintaining the limit, they’re actively making them thicker. I think they are trending in the opposite direction now.
And mind you, the iPhone 6 was the thinnest and it had the bending issue and all that… But the iPod Touch 4 was even thinner but had a much stronger body, was cheaper, and had the same A4 processor as the flagship iPhone at the time it was released.
It’s not impossible to make a super thin device that also feels good and is durable.