Do you have anything to base your rather rose-tinted view on: that spending yet more money on health and 'skills' would increase the UK's productivity?
Or is have you just fallen for the usual leftie narrative "Spend more! Spend more! Utopia is just round the corner once we're through this rough patch!"
Per person, real-terms funding of the NHS has consistently increased. Weirdly, people still say it's under-funded whenever the rate of increase drops. Ie it's still increasing, but not as quickly as previously
. Obviously that's not sustainable, without equally fast productivity growth.
And unfortunately, in real terms and per person, productivity is pretty flat. We're just about back to 2008 levels. Per person, that is.
Our overall GDP growth isn't bad, but our population has grown by 13% in the last 20 years (probably more - no one knows exact numbers of illegal immigrants, but they still use the NHS). And much of that is low-quality immigration: asylum seekers cost the UK £100k - £400k each on average over their lifetime. ( BTW, about 2% of international students go on to claim asylum. Suddenly those few tens of thousands of pounds from each international student aren't such a good deal for the UK.)
Even skilled migrant visas only require a salary of £35k (which is below the level where a person contributes more tax than they cost in state services) and can be as low as £25k for many, many jobs. here's the list of jobs with a lower salary requirement for skilled visas.
So the question isn't really where do you find the money to do it. ("Tax more! Tax more! Utopia is just round the corner when those rich people hand over yet more of their money! Doesn't matter that punitive taxes are already making lots of them leave: tax those who remain yet more!"
The question is "how do we use the enormous amounts of money the UK government already spends on UK citizens each year more effectively?" and "How do we increase the per person productivity of UK residents?"