That said, there is a night and day difference between FSD 12.3 that you experienced earlier this year and the latest version 12.6. It will still make mistakes from time to time but the improvement is massive and obvious. More importantly, the rate of improvement in the past two months has been much faster than before.
Yesterday I spent an hour in the car over three drives and did not have to turn the steering wheel at all except for parking. That never happened on 12.3. And I don't even have 12.6 yet, this is still 12.5; others report that 12.6 is a noticeable improvement over 12.5. And version 13 is scheduled for release in the next two weeks, and the FSD team has actually hit their last few release milestones.
People are right that it is still not ready yet, but if they think it will stay that way forever they are about to be very surprised. At the current rate of improvement it will be quite good within a year and in two or three I could see it actually reaching the point where it could operate unsupervised.