"Written on the box is that such a single bag is as sweet as 1.5 teaspoon of sugar, and it is a lie."
This statement of a fact you base on something, or it's because "3.5% Stiviol Glycosides" is "nearly stevia-less stevia"?
If a 0.8g bag is in fact as sweet as 1.5 tbs of sugar, then making a 1g package makes no sense.
If anything a package should be smaller.
Also, to increase the Stevia content also makes no sense.
Not everyone wants to sweeten more than 1.5 tbs worth of sugar, most people don't actually.
If you want to see the magic of marketing, look at the dosing of toothpaste in commercials and on containers.
You are being conditioned to use even three times as much toothpaste than is necessary.
Just so you can use it faster and buy more often.

ps. I know you're going to buy votes for this entry, so I will not up-vote it at this time.
Maybe later, if I see there's no bought votes, I might give a 100% Vote...