You have to put this into perspective, GM produces approx 200,000 3.0's per year. The LZ0 was introduced in 2023, ball park 500,000 plus have been produced. The LM2 had over 1,000,000 plus produced (Unofficial GM leaked number is a littler over 1.2 million).
How many of those have failed? No one posts when they walk out, start the engine, go from point A to point B without any issues. If they walk out, it doesn't start, it doesn't make it from point A to point B, they do post about about it.
I purchase at least 100 new vehicles a year, while purchase price is a consideration, cost per mile to maintain them is as much a consideration. There are 17 LZ0's, 2025 or newer, have over 50,000 miles on them, none of them have suffered any mechanical failures. If the LZ0 was such a failure you would not see any in my parking lot. Are there failures, yes, a very small percentage. We will never know the failure rate, manufacturers don't post the rates on their drivetrains for the public to see.
Maintenance is key, every vehicle in our inventory is serviced between 4,500 and 5,000 miles. Oil and oil filters every 4,500-5,000, fuel filters every 3rd oil change, cabin and engine air filters every 4th service. Only use OEM filters.
Things I have discovered were not worth the cost as there were no benefits shown when compared to other fleet vehicles, same year, same power train. Aftermarket dual or smaller micron fuel filters, none of them resulted in less maintenance, but the filters were a higher cost, which increased maintenance costs.
Air filters, while the intakes looked better than the OEM, none of them resulted in less maintenance costs. Tried a few tuners, not one lowered operating costs sufficiently to break even with the cost of the tuner.
Tried the oil collector, did not lower costs either.
Depending on the dealership, some mods will cause the dealer's service department to put notes for the vehicle in the warranty system. Some dealerships didn't care. I always like the rsponse from the aftermarket folks, tell them they can't do that per the Magnum-Moss Warranty Act. Ask them to provide the legal council to fight the manufacturer, they won't, so much for that.