I agree with a bunch of your
I agree with a bunch of your insights on GM’s decisions with discontinuing their Voltec hybrid and plug-in hybrid products but I don’t agree with some of your engineering evaluation here.
The second generation Voltec system used in the Volt beginning in 2016 was perfectly fine for use in a Prius-like application with more emphasis on a bigger gas engine and less emphasis on the electric power side of things. In fact, GM did exactly that when they dropped an only slightly modified Voltec transmission into the Chevy Malibu Hybrid. They only removed a clutch that would never be used in that configuration and revised the electric motors for better efficiency in a hybrid duty-cycle. The rest of the transmission was used unchanged. They could have just dropped in an unmodified Voltec transmission and it would have worked just fine the way it was without the tweaks.
Likewise, GM created a RWD variant of the Voltec for the Cadillac CT6 plug-in hybrid that was better tuned for use with a large gas engine and heavy torque and horsepower output. GM could have easily dropped that CT6 Voltec into its pickup trucks and large SUVs for use in hybrid and plug-in hybrid models.
There is no major inherent tow-rating limitation with Voltec or the older 2-mode hybrid transmissions used in some GM trucks and SUVs between 2008 and 2013. In fact, I recall offhand that some of those vehicles had decent tow ratings. Vehicles designed for the highest tow ratings were configured with better brakes and alternate rear wheel differentials that had higher final gear ratios to get higher torque multiplication so as to better launch or accelerate while towing heavy loads. The downside of the higher final gearing ratio is higher and less optimal engine rpms during highway driving which results in worse EPA ratings. The same alternative RWD differential game could have been used to improve the tow ratings for the hybrid trucks and SUVs but they were so low-volume in sales that GM didn’t bother to offer variants with higher towing capability.
There is nothing about the Voltec FWD and RWD transmissions that made them inherently significantly more expensive to build than the Toyota hybrid platforms they could have competed against. The real issue was scaling and volume production to reduce the cost.
Ultimately, my take is that GM decided they couldn’t and didn’t need to simultaneously invest in a major transition to many new all-electric vehicles in the next few years while also scaling up Voltec hybrid production to make it cost competitive. They chose to simplify their product mix by dropping hybrids.
This seems like a reasonable choice to me. In any case, they now have the technology in hand so they can always easily bring out hybrids again if they need to in the future.