One of the problems with Labs is that there over 10,000 ideas in there of which very many are duplicates.
The team is working through the old list to build up a data base of ideas that "new" ideas can be compared against.
However, this is a mammoth task, but the pile is slowly reducing, while also trying to catch up with an influx of "ideas" caused by "missions".
Labs is way better than it was, and will continue to improve given time.
Edit to add. If you find duplicate please flag them up - it will help speed up the whole process 😉