Because it is convenient! And because you can easily afford.
Lochen you have it yet anyway - because you can actually just tear off a roll.
I notice no difference (thicker / thinner).
Yes - it's practical, because you only the role does not always pick up aluminum foil from the kitchen. But where do you think I'll get her the water for the Bowl?
Conclusion: If you can afford it and will is - want.
"Steam" makes it all comes to no difference.
