Circuit switching is a connection oriented service meaning the communication takes place in 3 phases where in the 1st phase i.e. setup phase or connection establishment phase, the resources needed for the transfer are dedicated to the connection b/w 2 nodes only. Since the whole path is dedicated, so the data being transferred doesn't need to wait at the intermediate switches. The switches don't accept any data from other sources and is solely dedicated to this connection. So data transfer takes place at constant rate(given that there is a continuous supply of data during the data transfer period).
However circuit switching doesn't say anything about reliability. Connection oriented doesn't ensure reliability. Reliability is when the sources get back acks from destination. Though the probability of loss of data might be less but here no such feature has been explicitly mentioned.
