Literally does not matter at all. The car should not automatically jerk itself into a cyclist.

I agree, and I don't remember whether I had the blinker. I, however, also respectfully disagree as in all fairness we should drive 100% perfectly 100% of the time, but we're humans. Expecting 100% driving all the times is the worst as it puts strain on the driver (I say that as someone that's pretty strict on blinkers).

What is special is one time it was a one way lane next to the tram with a concrete stub down. I wouldn't be surprised if the anti-collision kicked in and applied lane assist even with the blinker.

At any rate, the principle of least surprise still applies: heavy machinery must not jerk unexpectedly to the side. Never ever ever.

My car (EU, 2018) makes a noise when I cross a line without using the blinkers but it doesn't actually do anything.

Also lane assist typically activates after 50-60 km/h (35 mph). I like the feature because it helped me develop the habit of always using blinkers. Most modern cars also have cyclist detection and crash prevention. So I believe these feature are still much safer than a typical driver looking at his phone.