If Apple open-sourced their connectors and involved other manufacturers and stake-holders, we might have had both. But the extra profits from accessories was obviously too hard to ignore.

That said, lightning is probably more complicated and expensive to manufacture vs USB-C, and then they would have had to either compete or compromise with the USB Implementers Forum[0] instead of creating something in their vision.

https://en.wikipedia.org/wiki/USB_Implementers_Forum