Main usage for Singaporean:
Outdoor adventures (local or oversea) - trekking, mountain climbing, diving, etc.
For occupation - uniform groups such as army, home team, workers from light (workshop) to "medium" industry (shipping).
Leisure activites (general usage) - cycling, fishing, camping, photography, maintenance work, etc
Collectors - you know who you are ;P
People who own high lumens flashlights, usually already owned flashlights from most classes (10400, RCR123, AAA, AA, 18350 1x18650, ...)
I saw some of u buy those 4 cells big flashlights. For collection only or really got use in real life

So big and few hundred dollars each. Though i'm impressed with their thousand lumens and beam distance.
For me i'm not really into collecting but on and off if i spot something nice and suitable i will get it. Mostly use it as a edc, nite trekking and traveling use.