Do you play the runs with the effortless finesse of Hofmann? "Fine" is all very well, but is it fantastic? Scales are certainly not a waste of time.
of course it is not "fantastic" (in French, "fantastic" has a lot of meaning, my teacher will use this word the day I play the nocturnes like Samson François or Rubinstein, which might happen some day, but certainly not by next month).
I can say that I personnaly think that I have a good control of sound, i.e. I am able to produce what I want.
I struggle a bit with speed, and I think that this will improve with experience, not by spending hours on scales. As an adult, I have not much time per day (1h or 1h30 maximum) so I need to concentrate on what work gives me the more return on time spent. So far, I think that spending time on the specific "runs" that I need to actually play is time better spent than working on scales (the fingering is usually not the same, because I always bump into quasi-scales with some "jumps" and the text book fingering is not applicable.)
That said, I welcome anyone that could explain me why it matters to practice scales, because I am open-minded, focused on the results, so if I have to do scales, let's go.
But so far I have only found three classes of people : those who say it is a waste of time (and some are/were renowned concertists, we all know about Richter for example, but I still read interviews in magazines where some concertist says she doesn't do scales); More subtly, there are people who say that doing them badly (unsupervised by a teacher) is a waste of time, eventhough it could help if it is well done.
And there is of course people that say that it is usefull but generally don't explain why.
So when I am faced with the problem of allocating my time on the piano, so far I choose not to do scales, but I am ready to change my mind if someone can give me the rationale and some sensible arguments for it.
Also I have the feeling (is it right?) that as long as you don't work on "virtuoso" repertoire where speed is a must-have, then you can probably live without scales.