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.
I tried a laptop with these, they don't always work in combos, like Shift+PageUp, or Shift+Ctrl+PageUp didn't work at all. It was so inconvenient that I just refunded it a day later and bought a Toshiba (they stopped making laptops at all, sigh).