I think this is more likely to be the case that Hybrids are dominated by Toyota/Lexus. See:
> Overall, hybrids have 26 percent fewer problems than cars powered by internal combustion engines (ICE). Some standouts include the Lexus UX and NX Hybrid and the Toyota Camry Hybrid, Highlander Hybrid, and RAV4 Hybrid.
and:
> Plug-in hybrid electric vehicles (PHEVs)... have 146 percent more problems than ICE vehicles. Still, there are PHEVs that buck that trend, including standouts such as the Toyota RAV4 Prime
> The paradox is that hybrids have MORE potential trouble areas than ICE but less reported trouble.
> All hail McLuhan.
That doesn't seem paradoxical, I'd never expect that just counting potential trouble areas is the right thing, things can be made more reliable by addition. Make a laptop without a battery and I'm gonna report a lot of problems stemming from sudden power loss. Put a battery in, that's a new potential trouble area, but even if I still use it plugged in exclusively, I'm gonna report fewer problems since I'll never have sudden power loss and have no problems downstream of that.
Maybe that's not the case with hybrids? I don't know, but it seems like it could be - any time some of the load is taken off some of the most physical components, the ICE and the brakes, it could improve reliability even though the systems taking the load off can then also have problems.
I spent some time looking at this and it depends which hybrid, there is quite a bit of variation in drivetrains even within manufacturers. As sibling comment [1] describes the planetary gear arrangement in most Toyotas is quite simple compared to a normal automatic transmission, and the traction motor/generator replaces both the starter motor and alternator that a plain ICE engine would have. At the same time the hybrid system makes gentler use of the gas engine and brakes so even though they are mechanically near identical to the ICE model they will probably last a lot longer.
All hail McLuhan.