They cannot even move 10 existing lines of code around without breaking it in the process half of the time.
I very much doubt they are up to the task of implementing any sort of plan with a reliability that allows to complete the work faster than writing the code by hand.
To be fair though, even if it's not costing me that much it's evidently costing Anthropic a pretty penny, I'm up to like $800 in spend on my $200 subscription in less than a week.