It came down to licencing. Apple wanted $1 per port in 1999, which was too expensive. Intel would rather develop their own bus (USB) than licence Firewire from

It came down to licencing. Apple wanted $1 per port in 1999, which was too expensive. Intel would rather develop their own bus (USB) than licence Firewire from Apple. Apple eventually caved to $0.25 but it was too late. Firewire was heavily used for digital video, still used for heaps of industrial cameras. Still very prominent in digital audio. The multimaster bus design, guaranteed timing and bandwidth (isochronous transport), and speed, made Firewire a winner. A Firewire 400 drive is practically twice as fast as USB2. So anyone who had to do lots of transfers used it.