The other difference was the Firewire did a lot more in that chip, basically offloading a lot of work from the CPU, so it was higher-performing and lower CPU us

The other difference was the Firewire did a lot more in that chip, basically offloading a lot of work from the CPU, so it was higher-performing and lower CPU usage. USB was made mostly by Intel, and they intentionally made it "dumb" so that the CPU had more work to do, in order to push high-performance CPU chips. But of course, the big factor was that license cost, which made Firewire devices cost more, whereas USB was very cheap to implement.