So there's definitely still overhead that can make small transfers infeasible, but it's getting better.
It has gotten very prevalent.
tl;dr CNAPS is a bank-to-bank system, but in effect means domestic CNY transfers between major banks should settle within 30 minutes.
WeChat Pay / AliPay are a bit different, more like PayPal (though not completely like PayPal).
If Zelle cannot make the transaction happen, it is out of the running. Full stop.
I've noticed a "fee: zero" statement on the transfer page recently. I expect there will be an actual fee in the near future.
It may change now that businesses are allowed to pass on fees.
Venmo could be obsoleted just by the banks having a better UX, which I gather everywhere but America already has for sending money domestically