Straight up buying expensive daily-consumption things make no sense to me. Even shirt merch is fine; it's something you know is a worse product at higher price. But when they try to go "legit" by selling shit like coffee it's just.. why not make better merch? Elvis did the whole ayyline merch company, selling legitimate clothes while still staying in spirit of his brand.
I think it's partially hubris and partially greed. Hubris in that some content creators believe that being a part of their fan's daily routine in something they consume (coffee, energy drink powder, whatever) regularly is allowing their fans to be closer to them, and that somehow like YouTube "
democratized" video to the masses (build it and they will come) you can upend some other industry by making a better product and with your platform of being a content creator you can promote it.
The greed angle of course is that for every fan you have who buys every merch drop you have you probably have a thousand who are fine with owning one tshirt or one mug. You make something that's subscription or consumable the satisfied people will rebuy when the subscription lapses/they run out.
The problem is that most recurring consumption merch you cannot be competitive with Walmart or Target or grocery store supply chains. You are not going to have the volume to demand deep pricing concessions, shipping/handling will eat into your margins too. The end result is that your product is going to be both subpar (to be cheap enough for you and your supplier to make money) and expensive.
Gamersupps as you said is an exception to this, because while it requires specialized equipment to make with a lot of upfront investment (where I can't just buy the stuff to make at home easily) the actual cost per unit for the powder is really low. It's concentrated so you don't get killed on shipping costs. And the general alternatives (canned energy drinks) are generally multiple times more expensive per ounce, so it actually works for the consumer too.
Funny enough, Gamersupps at least has stepped into the land of retarded merch by selling "
Gamer Soups" which are basically creator branded instant ramen. While inexpensive to manufacture, ramen is bulky for its light weight, so its expensive to ship. Buying a case of 24 ramen for $36 costs $20 in shipping. Add sales tax in there and you're essentially at $60 for 24 ramen packs or $2.50 per unit, which is completely retarded when I could buy shin ramyun at the local grocery store for less than 60 cents a cup.
(Also I loathe Gamersupps' relentless horny cups and labels. It makes me embarrassed to admit I've ever tried it.)