Hmm, when did you try it? FaunaDB and the cloud service have changed a lot in the last few years, and performance is always improving.

Typical write latencies in Cloud are in the 100ms range because the data is globally replicated. Typical read latencies are the 1ms-10ms range, because global coordination is not required, discounting the additional latency from the client to the closest datacenter.

If you experienced something worse than that recently, maybe there is some other issue going on.