Is scentbird a scam or do i just not know how fragrances are supposed to work?

I just got my first box from scent bird a couple of weeks ago and thought " this is a lot of cologne for just 1 month and they're sending me more nextr month?" I personally dont use a lot of it so when i get a new bottle it last a few months. After using the scent birds stuff i noticed that the smell wears off really fast. like way faster than any of my colognes ever have. I used to wear versace and it would last all day. i tried this other Versace for men and it wore off so quick. My question is do they just use dupe fragrances for the subscriptions so that you have to keep reapplying and run out so you have to get more? something just seems really off about them. Has anyone compares the same cologne they use with one from the actual branded bottle?