I'm sorry, but I'm not being obtuse nor making strawman arguments. I'm trying to explain an industry I'm familiar with. If you're going to start with personal attacks or calling my input "silly" I don't know why I bother, but here goes:

> Laptops for the most part are put together from standardized parts and you can exchange the major ones (CPU, RAM, storage and often even the displays) from one brand to another and it will work. And if you go to desktop computers the range of parts that can be swapped out between manufacturers increases even further (power supplies, graphics cards, etc).

You cannot swap CPUs between laptops, obviously, unless you get the exact same generation CPU with the same footprint. This fact helps basically nobody. It is true that some laptops are built around the same CPUs from a common vendor, but the same thing happens in cars too!

Major parts like transmissions are shared across many vehicles and vendors. The popular ZF 8HP transmission can be found in cars from Dodge, Audi, Jaguar, BMW, Porsche, Land Rover, Jeep, Volkswagen, and others for example.

This patterns repeats across many major components like Bosch ECUs. Automakers aren’t dumb. They’re not custom making every part for no good reason.

Many of the sensors and small pieces used in cars are generic and interchangeable. They're also available across a range of generic vendors.

Common parts like wheels and tires are standardized with small variations, much like the different RAM speeds in computers. Windshield wipers are generic. Cars take generic fuel and oil.

The point is: There are a lot of shared and common parts in the automative world already. Like your CNC example, there are some common parts where it makes sense, but you can't take the motor controller board out of a Haas and drop it into Mazak. You're familiar with this industry so I think you can see why demanding that all CNC vendors standardize their motor controllers and everything else would be a silly proposition. Likewise, I'm familiar with the automotive world and I'm trying to explain that cars do share a lot of parts already, but demanding that everyone conform to a single set of standards is a silly proposition.

You say that 'there are not 100's of different engines' -> but there are 100's of different engines, even within the same manufacturer and in spite of the core being the same it is often extremely hard to swap an engine of the same basic geometry because of the different sensors, bolt patterns and so on. It would be trivial to require those bolt patterns to be standardized and for ECUs to be standardized to the point that they could be swapped between vehicles. It is the - in my opinion ridiculous - differentiation that leads to vendor lock-in resulting in the fact that even though the underlying component is supplied by Bosch and it is absolutely identical you still can't move it from one vehicle to another because they spliced a different plug onto it and other lock-in increasing tricks.

The automotive world is full of such bullshit and given that there is no need for it (wouldn't it be nice to be able to swap an engine from any brand into any other based on a generic form factor and standardized interface) it is clearly all about protecting the profits.

When you go to a VAG garage with an Audi the exact same part from Bosch will be 1.5 times as expensive (as will the mechanic that puts it in) as when you go there with a VW. And if you go there with a Porsche the difference will be even larger. And of course there will be tricks to make sure that the cheap parts don't fit the more expensive model. And that's within what is essentially one company, once you go outside of that your ability to swap parts without access to a machine shop drastically diminishes.

That transmission you mention is a great example: you could swap it out in theory, but in practice the manufacturers have made it impossible to do so, parts have their own identity, talk to the ECU using custom protocols and so on.