I started using fountain pens a couple of years ago, and still do for my daily writing.
I write rather a lot; I don't bring my laptop into meetings unless I need to. Combine that with my handwriting being relatively neat, small, and stylized, and I needed something with a sufficiently fine nib, and ink that would flow well through it.
It turned into a fascinating optimization problem, during which I ended up down the rabbit hole of nib sizing (European nibs tend to run wider than Japanese nibs), notebook paper (there are plenty of good notebooks that are fountain-pen friendly, and that Moleskine notebooks are both comparatively expensive and the paper just isn't great), and different types of ink (which brands run "wet" or "dry", etc.)... and all of this is before getting into eyedropper-conversions, nib repair, and all of the other craft-related things one can get into.
I started with (and still have) a Pilot Metropolitan and a Platinum Preppy that still see use, although I've gone over to a Kaweco Special FP and a Pilot Vanishing Point (both with extra-fine nibs) for daily writers.
The current "daily writer" tuples are:
1) Pilot Vanishing Point (extra-fine nib), Pilot black cartridge ink.
2) Kaweco Special FP (extra-fine nib), Faber-Castell Carbon Black ink.
...preferred notebook is the Kokuyo Campus High Grade MIO notebook (A5 paper, 80 sheets, ~$6.50 each).
That all being said, I still use ballpoint pens on airplanes; the Pentel BK77 Superb (fine point, black) works just fine.