"The problem is that the sensor they are using today had the lowest image quality on the market – in 2016" Wow, that's substantial. On the market? Really? The E-M1mkII sensor was the WORST someone could find? Not so sure about that.
For anyone that spends time with the system, and the sensors...if that is the worst thing we can find about them...Olympus and Panasonic seem in good shape with their cameras. Yes we would all love improvements, and anything more is great...but those statements seem harsh and ignore the sum of use.
Two stops of depth of field over a full frame lets you be two stops lower in ISO for example to achieve the same look, which brings you back to a better set up. (unless you need the extreme ends in either direction) Comparatively there, I find it hard to see the major real world difference between the leading APC sensors. I've used them side by side.
Regardless, horses for courses as they say. Just seems to play the entire camera and system down for one item that isn't even extreme as this article makes it sound.