Why is copying a value from register to memory (or memory to register) "RISC" while performing some logical operation to the value to the value as moves "not ri

Why is copying a value from register to memory (or memory to register) "RISC" while performing some logical operation to the value to the value as moves "not risc"? I'd agree that memory to memory is "not risc", but given the amount of work necessary to do a register access, it's unclear why doing work on a value is "not risc". Datapaths are NOT the complex part of a microprocessor.