gm I think you are totally all over it. The CAN system certainly has increased the cost and complexity of a relatively straight forward device, the pickup truck. My 1977 does everything my 2015 does, my 2015 does everything a 2024 will do. If the headlights don't work on my 77' first guess is the fuse. In my 2015 hmm???. In a 2024, ya gotta have a diagnostic hook up at the dealer. If I want to "tune" my 77' some carb jets, a screwdriver, a few wrenches, and a timing light should be a great start. On the 2015, I have to hook it up to my laptop with an expensive program loaded. The CAN system on the 2015 interacts with the anti-locks and much more. If you wish to tune for a little more driver control, watch out the CAN system may take over and apply the brakes. Working and tuning on modern vehicles is beginning to feel like the movie 2001 a A Space Odyssey.