And that " Lack of space offered and taken by road users " is likely to continue well into the future until the % of vehicles with these features increases significantly. Hence the OP's assertion that he considered it dangerous for the vehicles behind.
Unfortunately these advanced computer systems are really designed for Autonomous vehicles when ALL such vehicles have the same abilities. In the meantime they have to be degraded to cope with vehicles that do not have such abilities and the fact that the fitted vehicle does not have the full Autonomous vehicle sensor package so the vehicle does not have Full situational awareness of the surrounding conditions and vehicles etc: and hence such episodes where they act for no obvious reason to the driver.
Unfortunately, many do not know how the system works or reacts and cannot themselves test if it is working so have to take it on trust.
eg: Standard Cruise Control maintains a steady speed ONLY. very easy to see if it is working or not. Speedometer and Cruise light together with Driver observation.
ACC, all the above BUT it also has the ability to slow/brake the vehicle. How do you test this Function will work correctly and timely? Is there a test function, No. Do you just depend on ACC not being available if this braking function is not working? In other words No News is Good News. There have been a number of Members stating that ACC Front Assist Braking being activated for No good reason. Do they now trust it to work when there is a good reason?
I personally think that these functions should be switchable, by the Driver, and also part of the Ignition On system whereby they are checked as functioning, both electronically and mechanical, and Warning Lights displayed if not. The Driver can then select which functions they want rather than the Total take it or not option given by manufacturers.