I routinely find that the finder is faster for local disk to disk copy operations than Rsync. For instance Rsync on a large directory (100gb with 14000 files) can take many times longer than the finder. On my setup I see it working around 20MB/sec whereas finder often gets me up into the 100+ MB/sec. I find this pretty frustrating because Rsync offers restart-ability and is much more ideal for my use case. Why is this? After all it should be the same disk io operations being performed.
Edit: Hardware involved here: 2018 maxed out MacBook Pro 15” with touchbar, 16GB ram.
Reading from internal SSD (2 TB) Writing to: OWC hardware raid 5 with 4x 6TB 7200rpm HGST drives Benchmarking writes to the raid using AJA system test is about 180MB/sec