I completely agree. I struggle to think of any legitimate business that would allow only gift cards. Maybe some privacy oriented VPN providers?
In any case, I think this is almost a willful misunderstanding. Not only does it attack the straw man of "no one ever gets legitimately paid in gift cards", but literally the first counterexample, Paysafecard, isn't a gift card!
Blizzard runs several popular games where you need to buy their currency before you can buy anything. I don’t know if it’s the case anymore, but Microsoft used to require Xbox Gold to purchase games. Usually this requires locking more up than the purchaser intended to spend.
I work with someone who does payment for adult sites etc and even though they do offer Paysafecard not a ton of revenue is generated through them, because fees for the creators are quite high and I guess it's just inconvenient.
Most people who want to spend their money just do it using credit card, bank transfer, whatever.