> all the ICE/electric interfaces are more reliable than a traditional transmission
The argument goes like this,
ICE cars have an alternator (electric motor 1), starter (electric motor 2), battery, and transmission. A beefier alternator (generator) + starter (electric motor driving the car) + battery adds less complexity than a transmission. That’s the simplest EV design where the engine only ever charges the battery. It’s perfectly viable for a long range plug in hybrid that only ever uses the engine on long trips.
The downside is batteries have conversion losses, so most hybrids have various ways of directly using engine power which then adds complexity. But ultimately hybrids are more complicated than EV’s but very much can be simpler than modern ICE cars.
PS: Technically some old ICE designs like dynastart used to do the same as hybrids where the same electric motor acted as a starter and alternator but in modern ICE vehicles the tradeoff around now little time the starter is needed and how little power the alternator needs to generate means it’s more efficient to separate it out. http://www.isettadoc.com/files/dynastart.pdf