Plenty of countries have higher taxes than the UK, and score higher on happiness/QoL metrics, too.
Personally I'd like the UK to be a higher tax, more socialist country.
There are many factors influencing everything, the reason taxes are negative is because the spending of those taxes is done on non-productive things, or done extremely inefficiently.
This is not to say this does not happen in capitalism too, take for example twitter, people think twitter was a business, but it was a activist organization, thats why 80% of staff can be sacked.
The comparison with twitter and the government is, the former gets funding easily from idiot investors, while the latter gets funding from idiot taxpayers.
You can see this sort of thing on a much smaller scale at normal companies through whatever the HR teams are doing.
Its not just the taxes its also the other laws which impact these sorts of things. I've lived in london for a long time, london needs to be taller (average building height) massively so.
The problem with tower blocks they built is not enough, when you build only a few, the poorest move its not good.
To rephrase this better, if i am absolute dictator i could achieve everything you want easily, however other people will not trust me of course, and this is why, rather than trusting the government to spend 40-50% of GDP via taxes, we trust the free market to do this instead.
Same as your side likes to ignore the fact that there are lots of low-paid workers paying more in rent than they would pay in mortgage repayments, if they could get a mortgage. And don't want to be stuck in that position, but can't find a way out.
And don't want to have the insecurity of being unable to prevent their eviction on a whim, but can't stop that, either.
The reason this happens is directly due to the government, and various finance rules and regulations, of which i dont know what they are exactly.
If truly your rent is so high and a mortgage could be cheaper and you've been shown to afford said rent, then clearly lending you money, thus reducing your overall spending on housing costs, while paying interest on that loan, is a win-win scenario.