You’re absolutely right, but I want to add that there are meaningful, practical differences as well.

The reality is that cruise control doesn’t tend to create accidents because by its very nature it still requires an almost constant level of engagement from the driver. There are very few places where you can run a vehicle on cruise with literally zero user input for more than a few minutes without starting to veer off the road. It assists the driver, but it doesn’t replace their role.

FSD does replace the driver, right up until the moment where the driver needs to step in and correct it. Psychologically, this is a very different interaction. Automation blindness kicks in. If we spend 99% of our time trusting the actions of the machine it becomes very, very difficult to maintain enough focus and attentiveness to recognise the 1% of times when we need to override the machine (this happens in all instances of human oversight over automated processes).