Save a few dollars, times 10's of thousands of vehicles in higher production models.
I've posted this before in more detail, but the short version is that when I was working at Ford Motor Co in the late 90's I remember seeing some internal documents championing how they saved ~$200 off a production Taurus (at the time a ~$20,000 vehicle) via a bunch of $10 and $20 individual cost savings. It was a big deal, added up to real dollars.
There is more cost savings than you might think in a simplified wiring harness.
Some 3rd party organization builds the harness, then it ships to the manufacturer, where it is usually installed by humans.
Besides the material savings of less actual wire, you most likely have labor savings on the harness build, and possibly on the installation if the new harness is easier to install based on the reduced overall weight and complexity.
The networking methodology side would likely not be overly complex. We already have CANbus device networks, and the associated software stacks. Changing to an ethernet based approach is a well-understood transition that would not require major changes, at least not beyond the incremental updates and other things that the engineers are already likely to be working on.
There are benefits weight and cost and system complexity and network specifications, etc. There are certain things you just cannot do with CAN bus that manufacturers want to do. Using traditional Ethernet is possible (and I've done it), but the second you bring it up to penny pinchers they get a headache and the conversation is over. Having something like this allows you to make the transition while not just increasing capabilities, but actually decreasing costs.
Dollars? You know that automotive calculate in 1/10 of cents. Every cable needs an appropriate connector. Every wire needs its dedicated pin in the connector. Did you know, that the connector housing is directly molded into the case because its cheaper?
Alone Ford at one point sold over 6.6 million vehicles a year.
So, you're telling me, the manufacturers would've switched to this new amazing way of doing networking in the car, but it would've cost them an extra dollar and added a few hundred grams to the weight of the car, so they just had to wait for this standard to come along?
10/100BASE-T1 and its relatives are a long time coming. Car manufacturers are actively making these standards, they aren't "waiting for it to come around".
And if it was only in one place, yea, maybe not worthwhile. But what happens if you save $5 each on 300 different systems in a production run of a million cars?
But you don't save 5 dollars on 300 systems, you save less, per car. The price and weight of the cables has very little to do with the decision to use this vs other ethernet standards.
Automotive manufacturers will spend 6 figures in NRE costs to save $0.003 in unit costs. If they only redesign every few model years, use the same hardware across several models, and they sell millions of cars per year, the math works out pretty well.
I've said it in another reply, but the automotive industry would've switched to this amazing new standard, except it would've added a couple of dollars to the cost and a few hundred grams to the weight of the car, so they just had to wait for this?
10BASE-T1S is more of alternative/replacement/upgrade to CAN and CAN FD, which use a single wire pair as bus, too. And automotive 100 MBit/s and 1 GBit/s Ethernet are also single-pair. (But they are point-to-point and therefore more expensive, as the article explains.)
