I am a trader. I know some website like binance, yobit, hubai, coinexchange etc. They have usd exchange but not available skrill, perfect money, netller, paypal withdrew option. Anyone can share some website then i withdrew my USD on skrill, perfect money, netller, paypal website.
I'm a US resident so I'm not sure if these option are open to others, but I can use Coinbase to send fiat to my PayPal or my checking account. There's also BitPay, I know they're available in other countries but that might be limited to your local currency.