Why does Samsung Magician write so much data
Solution 1:
The life is based on data written to the flash, not I/O performed by the CPU to the SSD. You are comparing two measurements of completely different things.
For example if Magician performs a status request operation to the SSD every second, a lot of I/O bytes will be written to the SSD. But none of the SSD's write life will be consumed.
The tool you are using is measuring the use of your computer's I/O bandwidth, not the amount of data the SSD's controller is writing to flash.