Early cell phone manufacturing was more automated than it is now. The "brick" type phones (Nokia, etc.) were a stack of boards with cutouts for the thick components. The whole stack was squeezed together and sometimes riveted. So the internals were well-supported and very tough.
That kind of assembly could be totally automated. Pick and place to make the boards, stack and rivet to put it together.
Modern phones have little pieces and wires all over the place.[1] You'd think these things would be designed for automated assembly, but they're not.
It was a short-lived experiment. Motorola was sold to Lenovo, and the plant shut down, within a few years.
[0] https://www.theverge.com/2013/9/11/4717796/made-in-america-a...