There was a period in time where Macbooks had FireWire 800 and USB 2. Apple chose not to be first with USB 3, so the choice was more expensive, fast FireWire or cheap and slow USB 2 devices. FireWire was significantly faster than USB 2, USB 3 was faster than FireWire. Eventually Apple dropped FireWire completely, and added Thunderbolt connectors. That did anger quite a few people who were invested in expensive FireWire devices. My favorite Macbook Pro was a 2015 13" it had USB 2 ports and two thunderbolt ports for high speed devices. Honestly, the only thing I ever used the thunderbolt port for was driving extra displays.
Things have improved by now, but my experience with the earlier USB 3 devices is that compared to their FireWire counterparts they were extremely flaky — wildly inconsistent transfer rates, intermittent disconnections, and general weirdness, especially for sustained workloads. I could see FireWire being preferred over USB 3 for that alone, even if USB 3 was faster on paper.
My experience with Firewire was that not a single peripheral I owned was compatible. So yeah, I probably would have preferred a few more USB ports instead of a dedicated plug for the iPod I don't own.
I still have my Firewire to Thunderbolt adapter in my random adapter drawer... worked a charm for my Firewire external hard drives and mixing desk. It did take quite a while for stable USB 3 peripherals to come out, and by that time I was ready to upgrade those 1 TB hard drives to 4.
edit: forgot the Firewire-... sorry, ieee1394-connected MiniDV camcorder!
USB 3 was a horrible janky mess for many years, with the early chipsets (and/or chipset drivers) being highly unstable. I recall being entirely unsurprised that Apple stayed clear of it during that time.
