How this power control circuit works?

Question

i've been looking at ESP32-GATEWAY from Olimex (Schematic here), i've seen that in order to power on/off the LAN8720 chip, they use a P-Channel Mosfet (WPM2015) and a Pre-Biased transistor (DTC114YKA), this configuration is a little bit unclear to me, i don't understand three main things:

• Why use a transistor to control the mosfet?
• How it generally works this configuration?
• Why they added the 10k-22uF capacitor from ground to source of the mosfet?

A partial screen of the interested circuit portion is below:

Answer 1

1. It is always a good idea to use transistor to control anything with any MCU as it minimizes the current that needs to be provided by MCU itself.
2. Here a small base current to T1 transistor (after MCU goes high on GPIO5) makes T1 conduct. So now there is a current path from +3.3V across R6 and R5 to ground. Which makes the GATE of FET1 also at ground turning it on. (actually voltage at gate is more than 0.3V if you account for R5-R6 voltage divider and 0.05-0.2V voltage drop from T1 Vce in saturation)
3. 10k R6 is there to make sure that gate voltage goes back to +3.3V AFTER the T1 is turned off (not conducting) by MCU. FET1 could and would stay on if there is nothing to pull it HIGH. So MCU goes LOW, T1 doesnt have base current anymore, it stops conducting. Now only current path is +3.3 to R6 to GATE of FET1. effectively GATE of FET1 is +3.3V