OK, fashion wise the waist pack is seen mostly on tourists at Disneyland; but for a planner/prepper/outdoors person its a simple, out of the way place to carry just the right amount of gear - some even include water bottle holders or a hydration bladder.
First we are assuming that I care about fashion. I am a preper, and I really care less about fashion, and more about function. Perhaps this will explain why I am single and have no life to the point of being a Sheriff on this site.
But in all seriousness the Fanny/Waist/Lumbar Pack is practical and functional. but remember that when you take it off, if you have to run, don't forget to grab it. Also I think that one of the larger issues with the pack is that so many companies made them of poor quality/design that they looked more the joke and fell out of favor.
Now a good Mountain Smith or LL Bean Pack that is of high quality can really even out the load and make everything much more manageable.
**Disclaimer, I have no affiliation nor interest in LL Bean or Mountain Smith, I use them as references as I have actual experience with here packs**