I carry two fixed blade knives daily during the work day. Plus the folder in my front pocket. And the small pocket knife in my front pocket. And since it's winter, plus the folder in my coat pocket.
The fixed blades are used for harder tasks that would be abusive to a folder, as well as tasks that you probably shouldn't do with a knife. Hammering, bashing, scraping, prying.
Are you a human auger?