Without reading the whole thread - The problem with (UK / Western) tax is that the tax burden on the UK citizen is huge compared to many other countries. This tax burden is compounded by the reality that Western (UK) approaches to tax make the 'established' western countries uncompetitive in the global markets, so they actually have to take more tax (on annually declining GDP expressed as a global %) to continue to maintain services (eg NHS), and it has created a race to the bottom for the UK.
The reason that the UK, US, EU etc. get so wound up about everyone paying tax globally is because in many other countries citizens don't really pay tax, which means they can take home more of their pay packet (and often more than the UK take home) whilst companies effectively pay them less. The net result is that the UK and West continues to remain entirely uncompetitive when it comes of global manufacturing and many services. The UK is trying to level the playing field by insisting tax is paid globally (via attacking big corporates, off shore accounts, trade agreements etc)., but this is a minority position globally.
This will no doubt be derided as nonsense by some, but having lived and worked in Asia for the last 15 years I can state that many skilled workers (by no means all, but many) in Asia now take home more for the same jobs as individuals in the UK, but are effectively 'paid less'. This maintains the competitivity of the Asian country / workforce in the global market. Taxes are raised by other means, eg. taxes on corporate profit, the take of which is much higher as a result of much greater local profitability, but is still levelled at a similar or lower % than western markets, so everyone locally wins and maintains competitive attractiveness.
Additionally a lot of western tax take goes to funding western debt, often to Asian countries (who further profit), so the net is that the Asian countries need less tax take, but have a cash surplus every year, whilst the western countries are floundering and borrowing more and more which inevitably requires a larger % tax take from the individual to maintain 'standards'..... big issues and a long term downward spiral for the UK.
In Vietnam (where I live currently) when we have beer conversations many Vietnamese are astonished by how little the average annual UK take home pay is, and how much tax UK workers pay, and yet the UK is ridiculously expensive to live in. VAT is 10% here as another example of tax disparity and petrol is about $0.9 per litre. Successful countries don't have to tax the population heavily to deliver services and growth, but declining economies have to tax the population harder to maintain standards...
The UK isn't in recession, but its economy is globally underperforming, and has been for 40 years. This is why the tax take is so extreme on the UK citizen, and there is an ongoing struggle to maintain services, which will only get worse. Wars used to happen for oil, now they are happening for economics.
I would have to earn maybe 50% more for the same job in the UK, to take home what I do here, but I pay all my taxes. I can then choose what services and insurances I want to spend my income on.