Our current video cameras are operating at the limits of current sensor technology. As a result there isn’t much a camera manufacturer can do to improve sensitivity without compromising other aspects of the image quality.
Every sensor is made out of silicon and silicon is around 70% efficient at converting photons of light into electrons of electricity. So the only things you can do to alter the sensitivity is change the pixel size, reduce losses in the colour and low pass filters, use better micro lenses and use various methods to prevent the wires and other electronics on the face of the sensor from obstructing the light. But all of these will only ever make very small changes to the sensor performance as the key limiting factor is the silicon used to make the sensor.
This is why even though we have many different sensor manufacturers, if you take a similar sized sensor with a similar pixel count from different manufacturers the performance difference will only ever be small.
Better image processing with more advanced noise reduction can help reduce noise which can be used to mimic greater sensitivity. But NR rarely comes without introducing other artefacts such as smear, banding or a loss of subtle details. So there are limits as to how much noise reduction you want to apply.
So, unless there is a new sensor technology breakthrough we are unlikely to see any new camera come out with a large, actual improvement in sensitivity. Also we are unlikely to see a sudden jump in resolution without a sensitivity or dynamic range penalty with a like for like sensor size. This is why Sony’s Venice and the Red cameras are moving to larger sensors as this is the only realistic way to increase resolution without compromising other aspects of the image. It’s why all the current crop of S35mm 4K cameras are all of very similar sensitivity, have similar dynamic range and similar noise levels.
A great example of this is the Sony A7s. It is more sensitive than most 4K S35 video cameras simply because it has a larger full frame sensor, so the pixels can be bigger, so each pixel can capture more light. It’s also why cameras with smaller 4K sensors will tend to be less sensitive and in addition have lower dynamic range (because the pixel size determines how many electrons it can store before it overloads).