This would be a good place to mention that even Tesla has long partnered with Panasonic to help with their supply of batteries.
"For a given volume of cars" still holds. If the world is buying more cars, the manufacturer of piston rings is losing the opportunity to expand their business instead of shutting it down, and is inclined to resist.
> What they may lose in cam shaft sales, they may gain in EV part sales anyway.
The whole point is that EVs have significantly fewer parts, and especially fewer moving parts that wear out.
> Battery sales.
The local supplier of bespoke transmission linkages for specific models of Toyota then has to enter into a global commodity market in competition with multi-billion dollar international companies like LG and Tesla and other commodity suppliers in China, South Korea, Germany or Texas.
> This would be a good place to mention that even Tesla has long partnered with Panasonic to help with their supply of batteries.
They did this when they were a tiny upstart with no internal production capacity. They're now constructing their own battery factories on three continents. Anyone converting their whole lineup to electric is likely to do the same because it's the single most expensive part of the car.
Denso (34% of revenue in traditional thermal control, i.e. radiators, water pumps, etc., also famous for spark plugs) will take a hit.
The thousands of much smaller companies that specialise in precisely fabricating minor parts (say, exhaust pipe mounts or engine mounts), less so. The expertise is not so transferable.
There will be change, and everybody hates that.
Traditional cars already have all of those things. For a given volume of cars, the quantity you need doesn't increase for an electric car. They're the status quo, not a way to make up for the loss of some other production.
And electric cars don't have cam shafts, exhaust pipes, fuel pumps, transmissions, emissions control systems, alternators, oil pans, spark plugs. That list is so very long too, and all of that is going away and not being replaced with anything.