Why do 72h and 96h deodorants exist?

Hygienically speaking, one should shower at least everyday or if you do nothing all day, every other day. Anything beyond that you should either take a long hard look at yourself in the mirror or you are the one exception that lives such an inactive life that you do not collect any sweat, dirt or oil throughout the day. But matter of the fact is, most people shower at least once a day, if not more. In most countries, even the more impoverished ones, around 80% of people shower daily. Once one showers, the effect of the deodorant disappears and any effect left over is so minimal it isn't possible to notice, prompting you to have to reapply the deodorant before the 72h or 96h are done.

Taking this into consideration, 72h deodorants and deodorants promoting a longer lasting are practically useless or at least a really odd marketing choice. The time a deodorant or anti transpirant can last isn't really necessary for everyday use as long as it's around 24 hours long. Marketing to the minority that use the deodorant do not shower everyday or are doing an activity such as camping is odd as majority of their users are not showering less than once a day.

There is also the argument that higher times make the product look more effective, such as 96h may seem more effective compared to 72h when it really is the same and has no effect. But I feel once again if you're smarter than the average 4 year old you would understand this has no altering effect on how it works.

If anything they should have the smell (or in case of anti transpirants, the percentage of bacteria killed) as the main selling point/big label on the bottle, but they don't. Why is that?