Re Diane, venting and QoL, it should not be overlooked that she still has enough hand movement to use a computer, and the ability to speak. The same is true for GB.
I admire Diane and her husband's adaptations tremendously, but as she points out, she has relatively slow progression, a retired spouse and an additional in-home caregiver, and breathing is not the only measure of quality of life. Each person and loved ones has a unique decision based on what life is like when breathing begins to require more than NIV. The decision is, in part, whether it is desirable to continue that life for the time being, though the commitment to do so can be ended later.
So yes, some PALS do have good quality of life on vents, but there is a whole range of variables going into that, far more than the vent itself.