How useful the electronic shutter is depends on the speed of the sensor. There are some that are really fast – very useful for video, but also useful for stills when using the electronic shutter. So sensors that are optimized for video will do great for stills too. There are also sensors with global shutter (again, mostly in cameras that are really good for video), which won't suffer from these limitations. Though IIRC global shutter has other limitations...
I do enjoy having the option of an electronic shutter, because in some instances the risk of rolling shutter is small. Say you want to shoot in a church, for example as a wedding photographer. The priest will love you, as will the couple you are shooting, as you aren't distracting nearly as much. Or if you are doing street photography. Basically whenever you want to be as discrete as possible. Also they enable ultra fast shutter speeds. Like 1/32000. No mechanical shutter is able to move that fast. I use it when I want to shoot with a wide open aperture in bright daylight, without using a ND filter, which would add optical imperfections, costs extra and is quite troublesome to switch back and forth.
On the Panasonic G9 there was a switch that could be assigned to different features. I have set it to the silent mode, where it would activate the electronic shutter. So with the flick of a switch I could switch back and forth, depending of what I need in that situation. With my GX80 I have to go to the menu, find the right item and change it. Nowhere near as useful.
Basically, what I'm saying is improvements that are useful for video tend to have benefits for stills too.
---------- Post added 26-10-19 at 02:17 ----------
Originally posted by photoptimist Actually, the "global shutter" issue is an argument against large format sensors. The greater the total area of the silicon, the harder it is to get a really clean signal from all the pixels in a short period of time.
Small sensor cameras will always beat big sensor cameras on specs like FPS, video, global shutter, etc.
Big sensor cameras will always beat little sensor cameras on dynamic range, high-ISO noise, and overall still image IQ.
Global shutter works a bit differently. They tend to integrate memory for each pixel, right next to it. That way they can truly capture the data all at the same time. Sony has developed a full frame sensor with global shutter, so it can be done.
The advantage of larger sensors is IMHO also that the lens does not need to be THAT sharp, as every pixel is bigger. If your pixels are miniscule, the sharpness has to be insane. Some of it is averted by using only the best part of a larger lens, however that way you are losing a key benefit of small sensors: small camera systems.
However in my experience Panasonic lenses, despite being relatively light and small for what they are, are quite sharp. Perhaps sharper on the same camera than similarly sized or larger Pentax lenses (excluding the limiteds etc.). Why that is... no idea. Perhaps it could be that Panasonic is doing a lot of lens corrections in software, and the lens is optimized for that. ie. whatever can be done in software, will be done in software.
I've also closely looked at the Huawei P30 Pro raw files, which are pretty sharp given that the sensor has 40 MP (and those are not wasted by the lens) and the lens is pretty small. Which is even more amazing as it uses a 1/1.7" sensor, ie. something not that small. However the vignetting from this lens is outright insane, with roughly 1-2 stops of light loss AND massive color shifts happening. Everything that's not dead center has a strong green tint.