For me it's mostly a sentimental decision. Back in the 70's pretty much every fireman and likely police officer carried a Buck 110. I started with one on my belt, but found it impossible to reach in a proximity suit. So I put another fitted with a Flickit in my right coat pocket.
After I got hung up on a safety line and couldn't reach my right pocket I slipped another in the left. Then as luck would have it, never needed either for anything serious, go figure.
Thinking back most of the firemen had a variety of things in their turnout or proximity suit jackets. Hos straps, spanner wrenches, snoopy wrenches, flashlight and so on. I started out with only a flashlight, but soon learned the guys were carrying these things for a reason. A couple started to carry two Bucks in their coat pockets after my little adventure. Did anyone ever use that second one. Who knows.