Oh yes: There are many issues still with electronic shutters. From readout speed to crossover leakage between pixel bins, and on and on. Electronic shutters work best as an adjunct to a mechanical shutter at this time ... They are good for extending the exposure time range, for preventing first curtain vibration problems in some circumstances ("Electronic First Curtain" in many TTL-EVF cameras solves issues of poor shutter design, for instance in the Sony A7 that I had). They're also good for some situations where you want the camera to be 100% silent, such as photographing a piano recital in a quiet hall.
But most of the time, they add no particular advantage to the shooting situation or quality of the capture images.