Actually, with respect to chips...
There's two divisible parts of building an IC (saying this as a person who had actually done this.. with a cast of many).
#1. Designing the device.
This is typically in Verilog or VHDL or some similar, more complex tool set, where one (actually, a bunch of people) are architecting, documenting, and laying out the device. It's a bit like writing software.
When I write software, being a EE, I tend to be very aware of the fact that each line of code, after compilation, becomes assembly code with JMP, LOADREG, indirect (machine) addressing, and all that jazz. Want a SWITCH statement? The compiler generates different code for one of them as compared to playing multiple IF/THEN/ELSE blocks.
When I'm writing VHDL - every line of VHDL translates into honest-to-golly NAND, NOR, AND, OR, D-Flip Flops, and so on. In addition, specialized VHDL/Verilog code can pull up different kinds of RAM blocks and all that; and, yes, one thinks hard about where all this hardware is going on the die that one is going to build. At the end of all this, the compilation process results in gates and such with signals, propagation delays, I/O buffers, and lots of floor planning.
#2. The Foundry.
The Foundry supplies libraries and tools to the people doing #1; what they get back from the designers is stuff that's extremely close to actual layout, but not quite. The Foundry people then take the design data and generate actual mask sets that are used for photolithography; and these, then, are actually made into actual silicon (or GaAs, etc.)
The serious, billions of dollars of construction, care and feeding, and making it all work: That's in #2. #1 is coding, tools sets, simulation (the actual device files bounce back and forth between the chip designers in #1 and the foundry types in #2, refining the design, doing simulations, Simulations, SIMULATIONS until everybody on both sides of the fence are ready to die. Mind you, a good deal of the expenses in #2 are, when going to a particular sub-nanometer technology, is building test chips with all sorts of gates, memories, I/O buffers, and what-all which then get characterized. The characterization gets stuffed into the libraries that get handed to #1, designed to work with the design tools (Synopsys, Mentor Graphics, tons of others), and then the #1 types do the design.
Tesla designed the neural network chips for the computer in the car; but they didn't run the foundry. The foundry, an outside company, built the actual devices, and both crowds validated working silicon.
Costs for the #1 crowd is expensive in people, software seats, and specialized simulation and design support hardware; but it's not billions of dollars.
And, if you're wondering, the fact that Intel still does both #'s 1 and 2 is a continuing source of amazement to the industry at large.
Thing is.. Once one has a working silicon design, the cost per chunk of silicon is very, very small. So doing #1, despite the expense, only makes sense if one is going to buy zillions of a device. If you're only going to do 1000 of a chip, you buy somebody else's FPGA with the right feature set and pay $50-$1000 per chip. If you're going to buy 10 million, then it's cheaper by far to pay the NRE (Non-Recoverable Expense) to the Foundry people for the first hundred devices and pay your design team to work their butts off for a year or more.
So, consider Bosch. They do engine controllers. And the devices they design (assuming that they don't just buy a general purpose controller from somebody else) they sell to everybody who'll buy the box with the chip in it. They can sell a million each to three or four different car companies and make money; if the car company tries to roll their own, they won't beat Bosch on price since they'll have the fixed costs to get the design done, but won't have the volume to make it better. Hence, while I could be wrong on this, I betcha none of the big car companies do any of their own silicon designs (#1), because they can get the same, changing slowly over time, designs built by a specialized design house (a la Bosch) who can sell to all the big design houses.
Which is fine, reduces the cost of manufacture - but, when something Really Different shows up, like the neural chips Tesla is building, this whole incestuous relationship between the car companies and their suppliers falls apart:
1. The car companies don't even have #1 design teams. They have system integrators that mess around with catalogs of what the likes of Bosch & its competitors are building, Even if they wanted to do the whole-car-make-it-go-on-a-test-track, they would have to work with a selected supplier to get the silicon built, knowing all the while that any technology so built would also be going straight to the car company's direct competitors. Ouch.
2. The companies like Bosch who actually have #1 design teams would have to spend serious money with no guarantee they're getting it back, and they don't have, really, the knowledge that the car companies do. What do they do - partner with one car company? They could get stuck into a contract where any new stuff is only shared with that car company, and no other. That wrecks their whole business model of selling to everybody.
3. Eventually, the two points immediately above will get sorted - but this is one place where Tesla's vertical integration must be driving their competitors absolutely nuts.
4. Let's get this straight: Nvidia, a graphics card company for crying out loud, is a direct competitor to Tesla in the neural, self-driving computer space. Why? Because they make really, really, fast CPUs and parallel processors for (wait for it) better game playing on PCs. This is not stuff optimized for driving a real car around: It's stuff that's just close enough so that people without a #1 design team and the design rules to back it up can get something, anything out the door so they don't end up in the trash heap of failed businesses. I got no doubt that an Nvidea-based driving computer can do some self-driving; but is it going to be as good, or as cheap, as purpose-built silicon designed from scratch for the purpose?
This is what it looks like when your competitor is literally a few years ahead of you and you don't have the human and technological resources to compete. Because, when you did have them, you looked around, figured that nobody else needed to spend any money on New Stuff anyway, and fired them all, instead of competing because ten years down the road the barriers to entry were going to be low enough that a real competitor would show up and wipe you away.
You might have a chance if, when that competitor got started, you got started, too - but, from all accounts, the Big Iron Auto Companies spent most of their time saying, "Tesla will never succeed!" and staring at their navels.