I have worked on some hard engineering problems in my life, where one could not have been sure if it is possible to find a solution. In my experience, when you get to a "From here on it is just more of the same" situation, that is a strong indicator that a solution will be found in the near future.
And that is the feeling I get when I watch FSD videos these days.
5 years ago, people were celebrating lane changes:
https://www.youtube.com/watch?v=u7jNHFwZ3Ec
Nowadays, FSD drives through all kinds of weird scenarios:
https://www.youtube.com/watch?v=LISLFHCPWrw
And people complain about specific situations FSD can not handle:
https://www.youtube.com/watch?v=OT2H42k7Z1g
I'm pretty sure someone at Tesla sees this and thinks "Hmm.. we can solve this in a similar way we solved lane changes".