why did you power the circuit using usb port?
If you attach a 5v source to Vin pin wont it work/what are disadvantages of connecting it yo Vin pin?
can a 4 channel 5V relay be operated satisfactorly if i power it from usb port?
You can either power the ESP32 directly with a 3.3V power source in the 3.3V pins. Or you can power the ESP32 with 5V in the VIN pin or USB port.
There aren’t any advantages or disadvantages of connecting 5V directly to the Vin pin… Yes, you should be able to control a 4 channel 5V relay.