I use knives mainly for cutting open boxes, paper, and plastics.
I stopped carring tanto bladed knives as a work tool because I found its less acute, broader point less useful in penetration than more conventional shapes. Tantos survive penetration on some materials better than, say, a drop point, but they don't penetrate as easily on many materials I deal with. If I were expecting to use it in combat against someone who might be wearing body armor, a tanto might be a better choice; for my real world they don't work as well for me.
Which isn't to say I don't think they look really cool...
Anywho I've found thet a truely straight edge does have its uses; one thing I've found tantos excel at is peeling off price stickers from products. Depending on the material they are stuck to, if I'm unwilling to damage the product and it has a hard surface I use a tanto point. Think about things people collect; I use the secondary edge of a tanto for this. I guess there's probably a better way to explain it but I'm really tired... hope you get what I mean.