The part where it doesn't happen, but even with people moving in front of you, you're still in control of your following distance and speed. If they move in front of me, so what? They'll be at the following distance I'm maintaining because they're continuing to move faster.

And even then I'm probably still at or above the speed limit.

So, not only would someone have to cut in front of me, they would then have to match my speed, and then progressively slow down more than me to keep me at an unsafe following distance, and eventually we'll be stopped on the freeway.

But if the driver keeps going, then I'm still where I need to be.

(Note: I still have no problem doing this while maintaining the speed of the general traffic around me)

I've heard your arguments about people cutting in front of you, many, many times, and to this day, having driven in many different locations in many different types of traffic, I've yet to have that happen when doing the things I'm talking about. So you can go on saying how it's not possible and I'll go on doing exactly what you think isn't possible anyway, without issue.

(Btw, my adaptive cruise maintains an even longer following distance at its max setting than I do, and even using that I've not had people do what you've said)