In that sense, Firewire is less analogous to a Lambo ("a better car"), and more akin to a truck. But a very tiny truck, designed for both off-roading and portability. Which is to say: an ATV.
An ATV isn't better at being a car than a car is, but it is better at being a truck than a car is (though worse at being a truck than a truck is.) But sometimes, especially in constrained environments (e.g. search-and-rescue in the Alaskan wilderness), a truck won't fit, and a car won't work. So you need an ATV. It's well-engineered for that particular set of constraints.
Which is also the deal with Thunderbolt: it's PCI-e, but smaller and ruggedized, for places PCI-e itself wouldn't work (like a laptop), but where you nevertheless still need PCI-e -alike performance and bus semantics.
Even including an optional 5V power pin would have improved this situation, and could have put FireWire in a similar situation to Thunderbolt 3 now, capable of functioning with both high-end professional equipment and ordinary consumer devices.
A Lamborghini is full of flashy, pie-in-the-sky engineering that often ignores practicality in favour of flash and performance. On paper, it's a beautiful machine, but much like in the case of FireWire, it doesn't meet eye to eye with the real world around it.
The Toyota is less ambitious, more constrained by reality, and while it certainly doesn't match the on-paper specs of the Lamborghini, it is in every way more practical and viable as a system.
I would consider the Toyota to be the better engineered of the two when looking at them as cars and not as toys, even though it lacks the technical wow factor.