IMO scent control will give back what you put in it! Lackluster efforts will get lackluster results. First off there is no eliminating your human scent, simply cant be done. You can however significantly reduce the amount of scent you leave behind and put off.
I also agree that if a deer gets directly downwind and your scent stream hits them in the nose, they will smell you. Now how strong of a scent stream they get can be controlled atleast somewhat. The huge difference in reactions that people often discusss here, from "the deer was directly downwind and never smelled me, even after I hadnt took a shower in 3 days and wore the same clothes all season" to " I did everything I could and the deer still smelled me even when the wind was in my face" comes from different deer. Meaning each and every deer have their own personality, and some are much more wary and sensitive than others. Case in point is when you sit a stand and watch your entry trail. Having 5 different deer cross that path in the same exact spot, will likely get you 5 different reactions to your scent trail.
Im of the opinion that, while I know I cant eliminate my scent, reducing it as much as I can within reason definitely has its benefits in many situations. If the right deer hesitates just a second more before he pegs my scent, mission accomplished, as it may be the 1 second I needed to kill him!!! Besides that, showering often and wearing clean clothes is my daily routine anyway, not a big deal to do the extra steps for me!