I wouldn't call the whole of China a niche. International transfers from there aren't expensive but they're mostly impossible by official means. Banks don't allow citizens to send money overseas except for a few specific and verified reasons, which importantly don't include gifts to family members or buying things (eg real estate).
The Bitcoin blockchain is slow (as all blockchain are, relatively speaking) but most Bitcoin transactions happen off-chain, for example at the many Bitcoin exchanges, where bitcoins are transferred between customers at thousands of transactions per second using a central clearer (the exchange).
By depositing bitcoins at an exchange, you exchange it for that exchange’s Bitcoin credit, which has no limit on transaction speed, and when you want out you redeem your credit into a Bitcoin transaction.
This page shows the USD price of the credit instruments of the various Bitcoin exchanges: https://bitcoincharts.com/markets/currency/USD.html — e.g. a Bitcoin on Bitstamp currently costs 2439.84 USD, whereas the price of GDAX (Coinbase) Bitcoin credit is currently a bit more expensive at 2456.44 USD.