[hedgehog]

This is not true, at least for the most popular Toyota hybrid drive train. It's probably got fewer moving parts than the ICE counterpart by virtue of dispensing with the automatic transmission. See sibling comment:

https://news.ycombinator.com/item?id=38466406

[zik]

Check this diagram and tell me it's simpler than an engine and transmission.

https://automotorpad.com/toyota/83449-funcionamiento-sistema...

It's essentially an engine, a transmission, another transmission (power split device), a drive motor and a generator.

[hedgehog]

Most of the images there are broken, all I see are some conceptual block diagram type things. Find a teardown of the hybrid unit and compare to a teardown of any automatic, look at the actual internal complexity and moving parts. I was surprised. Here's a video of the P710: https://m.youtube.com/watch?v=O61WihMRdjM