In some cases people end up buying coins at a fee of around 5-10% due to the fact that they haven't got any other option than this.
Just to be clear, Skrill itself doesn't accept Bitcoin. Skrill just seems to have a friendly policy towards crypto in general which of course is a nice change for once.
You can only deposit BTC into your skrill account. You can't withdraw money from your skrill account in the form of bitcoin. It's quite typical really. Everyone is happy to take BTC because it is an irreversible payment method but few will give you BTC in exchange for your dollars.