A few thoughts: we're not that poor, a lot of the current distribution of wealth and government spending aims are the result of neoliberal ideology first and foremost.
That said our nominal GDP growth has been harmed by neoliberal policies which have shifted the UK away from producing very much and towards playing many silly games with money. We measure how much we move abstract representations of currency around (which usually represents some probabilistic measure of value of money, which in itself is really just numbers with no intrinsic value) and go "hey, great job, we've really grown the economy!"
We saw the financial crisis in 2008 and apparently thought to ourselves "let's have some more of that".
So we're in a situation where our overseers are seeing our GDP failing to grow as it should, panicking, and implementing more of the same policies that cause that situation in the first place. The UK isn't poor yet but it will be soon. The young and the poor are the ones who are feeling the bleeding edge of this trend but it's filtering through to the middle class now as well.
Yeah I think the main driver is neoliberal austerity doing what it does. The wing of the party in charge are basically Thatcherites. They want to the market to decide who gets access to basic necessities and bureaucracy to decide anything else.
In general I think neoliberals are becoming embarrassed by the fact that evidence based medicine is increasingly at odds with capitalistic ideals around how workforces should comply with the rich. So they want to introduce an apparently technocratic (which will inevitably be as low skilled tickbox bureaucratic as you like) body to replace actually qualified people - doctors- in this area.
I think it's also a bit of a reaction to changes in the geopolitical scene. They're hoping that in the event of further war in Europe that desperate but physically able people will be coerced into the military. By taking the ability to decide who is sick out of the hands of doctors and into the state they make this a lot easier. Similarly, more money for manpower and munitions by not paying out in benefits.