It would be great to have some useful information about the failure condition for FSD in this situation but the author provides essentially nothing.
> The car was making a turn. Something felt off—the steering wheel jerked one way, then the other, and the car decelerated in a way I didn’t expect.
I use the latest FSD in an M3 and I have noticed it behave indecisively when changing lanes, not so much when turning, but I believe the author's account.
> I turned the wheel to take over. I don’t know exactly what the system was doing, or why. I only know that somewhere in those seconds, we ended up colliding with a wall.
The author disengaged FSD (reasonable when concerned) and ran into a wall.
I almost never let go of the steering wheel when FSD is driving. I want to be able to take over with the minimum delay. I don't know that I'll ever trust it to drive unsupervised.
It's an unbelievable driver-assistance system. But you need to treat it as such. Tesla may market it, and name it, otherwise, but anybody using FSD should quickly realize it has limits.
Also have your same concerns / complaints with lane change hesitation on the latest FSD in a Juniper Model Y; the car puts the blinker on and then acts super-duper nervous, almost as if it were driving for the first time.
That said, I only notice this behavior in the "Standard" FSD profile. When I bump it up to "Hurry" or "Mad Max" the confidence is 100x. Not sure why, exactly, but this may help you. The only downside is that "Hurry" loves to speed and "Mad Max" even more so.
Tesla lane assist tried to steer me into a 3 axle gravel truck at 70mph when it drifted into my lane and I went partially on the shoulder to avoid it.
I wouldn't be so hasty to exonerate the software with suboptimal vision only sensors.