"the cost to use the technology is practically nothing"
Your data isn't nothing. Wechat eg. wants access to pretty much everything on your phone & you can bet that this data is forwarded to anyone (either with money or power) interested in no time.
Most Chinese may not care about privacy, but if you do, you shouldn't use stuff like Alipay or Wechat.
& cryptocurrencies in the PRC is a topic of its own...
It's only a matter of time until a more complete crackdown by the government, I suppose. Only government-issued cryptos (probably not much crypto in it) will be allowed.
Good points. I just wanted to add a little to the topic for those that don't know China that well. I think some cryptos can find a market in China doing other things besides being used as a currency to buy everyday items. Alipay and Wechat are too dominant in that arena IMHO.