I think it's totally a matter of preference. I only add fringe if a recipient says they would like it. For myself, never. In my opinion, after a couple of washings, no matter how gentle, fringe looks terrible. Some yarns fray and puff out (like Homespun). Others just look ratty. If I really felt that something for me needed fringe, I'd probably improvise a crocheted fringe, like ch 20, sl st in each ch, then sl st to the piece and so on.

I also prefer not to add one. They tangle and are a general pain in real life use. You can also do a picot cast-on and cast-off for a decorative edging.

Here is a link that might be useful: Picot cast-on and cast-off

Fringe or not for me depends on, first of all, the recipient's preference (if they have one and I know it), and then on the pattern and yarn. For most scarves I don't but sometimes it just really makes the scarf "pop." Overall, though, I skip it if it doesn't make a difference or isn't requested, for reasons others have mentioned.