EU added "cybersecurity" requirements in response to Comma.ai that means that a lot of ECUs going forward use signed messages AND often crypto key pairing against an onboard security auth box. The pairing process often require something like a scuffed up manufacturer rental Panasonic Toughbook with weird half baked apps and passwords. The car would refuse to drive or whatever if the owner wouldn't play along with that game.

> Power electronics are still modular and are easily swappable.

Depends. These parts are custom designed, physically, and difficult to find off-the-shelf replacements for.

The heater fan-controller on my wife's SUV died. This is simply a current-limiting device: receives (I assume) CAN signals from the dashboard rotary encoder and determines what current to send the fan.

While I could have dragged my 'scope to the car, determine what signals it's getting from the dash system (all integrated, btw), it was easier to find one in China and wait six weeks.

(I may have chosen the first option if this happened in the winter, but in summer the heater is never used anyway).

>Power electronics are still modular and are easily swappable.

Only if someone makes and sells those power electronics to you along with the appropriate DRM tools required for calibration and pairing with the other electronics of the car. Otherwise you're shit outta luck.

>Mechanical parts are more integrated, but they so simple that they can last for decades.

Simple != decades of reliability, when the design and manufacturing quality are piss poor in the race to the bottom for cost cutting and shareholder returns. Timing chains were also supposed to last a lifetime but plenty have been recalled due to know timing chain issues from manufacturing quality.

VW and Kia/Hyundai EVs were found to use custom dimensions motor bearings that can't be bought on the open market from anywhere, so only the OEM and their dealers can get them via their supply chain.