Digital.
I've saved on so much paper since I started doing digital. I hate wasting so many trees from all the plain white paper, sketchbooks, and loose pieces I've consumed over the years. I also tend to lose them, get them crumpled, folded, or dirty if I toss them somewhere randomly.
Skill-wise I think I've regressed a bit since digital mediums allow me to take shortcuts I previously could not. I can use custom brushes that instantly give me patters, feathers, sparkles, and even objects like clock gears or zippers that was previously a pain to draw consistently.
It's overall speedier since I can undo quickly instead of using white-out, and the fill bucket has been my best friend for the past 10 years.
I don't hate on traditional, since we all started with it. I really admire those who can still do amazing traditional artworks with inks, watercolours, and markers since I don't have much patience for it myself anymore.