Item or Row Numbering in the Outliner
Numbering in the outliner is something we already have slated as a potential feature down the road. We can't make any promises about it---it's actually more complicated than it might seem on the surface. Remember that not everyone uses Scrivener with a One Item Per Real World Thing philosophy. Some people have things broken down quite a ways below any surface topology that the reader would be aware of. So it would mean a more complicated hierarchically aware outlining label system, something like Word provides---though far less complex would be nice---and then you run into problems with what, if anything, this has to do with the actual output, i.e. the compile settings, which are agile and can be swapped out on the fly, causing dramatic shifts in the final topology of the document. Then you've got the matter of "Include in Compile" and filtration settings in the compiler itself which may omit chunks of what you see in the outliner.
You can maybe see why just relatively numbering a flat list of index cards, always starting from 1, was the implementation currently chosen. Trying to make those numbers reliably usable as a real-world utensil is rife with difficulty, and may never be fully dynamic (cf. the linked footnote numbering system on the Mac, which only prints footnote numbers after they have been compiled, and does not update them dynamically until you compile again).
But like I say, it's on the list for deeper thought, because nobody disagrees with you in the utility of numbering sections. That's just universally useful to writers and thinkers of all stripes.