EVs are quite unlike most residential power systems you encounter. They use high voltage DC, which this video illustrates, is a fun topic in of itself:

https://www.youtube.com/watch?v=Zez2r1RPpWY

To generate this, the batteries have more than a hundred cells wired in series, if any one them fails, that means your battery's dead.

In addition to this, the inverter that generates the AC driving your motor needs use high powered IGBT to switch this huge current and power tens of thousands of times per second to do PWM and uses filter caps to smooth the output. Both these are wear items(and impossible to replace) , its the operating conditions that determine if they'll live for 50 years or less than 10.

Which is why I think EV reliability will be no different from ICE - manufacturers who do give a damn will make them last long, and make them fixable once they break, while others will save a buck and won't.