First, arguments that the NHS is becoming unaffordable have to be viewed with caution. The UK spends less on health care than many other countries. For example, from 1977, the UK has spent less of a share of its GDP on health than either the EU average or the average for countries of the Organisation for Economic Co-opertion and Development. We spend about half as much as the US on health care (http://www.nuffieldtrust.org.uk/data-and-charts/uk-health-spending-share-gdp).
In addition, claims about demand can be misleading. For example, it is often cited that the NHS is becoming unaffordable because people are living longer. But older people are fitter and healthier than in previous decades, they contribute more to the economy than they take out, and account for a relatively small amount of any increase in spending in recent years (http://nhsbill2015.org/wp-content/uploads/2015/03/Myth-of-Ageing-fact-sheet.pdf).
Second, the ‘reforms’ are not necessarily about addressing rising demand and treatment costs. This is particularly clear with the Health and Social Care Act which did nothing in this respect: it was much more focused on restructuring the NHS and making competition mandatory in order to allow increasing levels of privatisation. The Five Year Forward View (FYFV) calls for a variety of measures (e.g. increased patient ‘self care’, initiatives to prevent ill health, £22 billion of efficiency savings, a ‘flexible’ workforce and new models of care that control costs) to close the gap it calculates between demand and funding. However, it ignores some of the significant drains on NHS funding, such as the Private Finance Initiative and the costs of running the NHS as a market, suggesting there is some other agenda. Many critics say that ‘reforms’ like the FYFV are more about dismantling the NHS in order to have an insurance based system, rather tackling rising demand.