The shown complex solves the connecting 3.3V SPI memory with 5V microcontroller. As the Translator of levels of outgoing signals uses 74HC4053, and for the entry signal 74HCT14. Both chips take power from 5V. Power supply 3.3V for the memory has been solved with the discreet stabilizer with TL431.
Complex was able will be reduced for one inverter (74HCT14-pin 3 and 4), but then needs take into account that the signal TO with the memory will be inverted.