I still use them regularly, and will buy one if one breaks or something like that. I use cloud storage most of the time but frankly I don't trust it completely for privacy as well as access reasons, and my storage needs would be pretty huge, so I backup files on a flash drive as a kind of second backup. I also use external SDD drives, but only periodically as they take up much more space and I don't lug them around. I can fit a flash drive in my coat pocket when I'm traveling, and so forth and so on.
I guess I just like redundancy, having control over my own physical storage, have a sort of backup routine (cloud for super frequent temporary storage, flash for less frequent more capacity, and SDD for even less frequent even higher capacity) and flash drives are super portable. I tend to buy them in the biggest fastest format I can, and pay extra for a brand name from a vendor I trust.
I suppose I could use my phone; I hadn't thought of that, but I like to leave as much space as possible for stuff on there, and I'd still not want some backup for that.