Britain’s future is being compromised by the massive increase in long-term sickness among the working age population

Not sure I would call 36% to 37% incativity a "massive increase" given the fluctuations in that graph, but it is meaningful.

Do we know for sure that all/most of this is related to the physical effects of COVID, the disease, specifically? Is it possible that the pandemic simply increased the amount of reporting for long-term health conditions? Like, it became more normalized to report that sickness was the reason for unemployment rather than some other reason? I wonder if, among some people, there is a little bit of stigma around admitting to having long-term disease as a matter of self-worth, or worry about poor reactions from family or friends or colleagues, or something else; and that could affect reporting.

I also wonder if the pandemic just discouraged some people from working. At all. Like just adopting NEET lifestyles - it feels like this is more common than it used to be. (I'm not saying this as a "people are lazy" thing - just an observation.) But I don't know if it's true in the UK. The decision to work or not work isn't solely because of physical health, it can also be mental health, or just a decision not to work that someone attributes to health reasons... maybe due to stigma of being a NEET? IDK.

The article seems to imply that this is exclusively a pathological issue with COVID, which I understand given the spike in some of those charts. But I hesitate to draw that conclusion and nothing else, merely because there are lots of contributors to long-term health issues in our society, including severe, extraordinary obesity, extremely sedentary lifestyles, perhaps effects on skeletal structure and posture/eyesight as a result of desk jobs and screens, and other factors. I feel like it would be important to determine to what extent the pandemic (and lockdowns, and interruptions to working life) was a contributing factor to this change as opposed to strictly physical conditions. Not sure if that can be done with the data available though.

I bring this up because if part of the explanation for this change in data is cultural, rather than an increase in the physically disabled population, the ways governments and companies respond are going to be different. You can incentivize a NEET to work with a higher income, maybe, or inspire them with a great self-help book. If someone is disabled and literally cant work, the government has to support them with different/better healthcare, timely access to which is already a problem in the UK.