There are certain models of GM cars and trucks that require the techs to have a special certification. Our Volts, Diesels, and ZR-1 are among them, our other ones have not.
And not all dealers get an allocation for every model. This system blows. I should be able to do like Tesla, and order my car from the factory, then have it delivered at my closest dealership. But that is illegal in many states, and broken in others.
However, thinking GM has a poor service network is simply not accurate, or thinking they do not offer customer care after the sale.
There are issues with OEM service with all brands. Some brands do not even require specific certification/training on their EV/Hybrid/diesel/track machines.
What I can tell you, is that if I have a 10 year old car from any major mfr, that requires major work, I have my choice to go to the factory for service and parts, or the aftermarket. It doesn't matter which brand. Heck I can do the service myself (which sadly, is often what I do to insure the work was performed to my expectations if a vehicle is past warranty).
I do not know what I'm buying this year yet for personal use. What brand, what powertrain, what family group. I don't even need another vehicle, but I'd like one. Tesla is still on the table, but obviously not a Model 3, since they are unlikely be available.
EDIT - I've read a lot of assumptions on the Internet about the Bolt. The lack of service is a new one. The older ones are: it's a rebadged Korean car, it will remain a fire hazard, it won't have the range they claim, it will be more expensive, it won't be available before the Model 3, it is too small, it's too big, the name is bad, it is ugly, it's a repowered edition of the XXXX ICE model, etc, etc, etc.
Let's see what a Bolt actually is in Retail Trim before we decide the aero is equal to a garbage truck, it goes less than 100mi, is sold with no heater, and is made in Russia, eh?