> but there's a factor of cant pay the creditors and you just stop

in the UK case then £895 of the debt is owned directly by the bank of England. So in the case of about 1/3rd of the debt the 'creditor' is your own central bank.

The government can of course pay interest on gilts by simply issuing more gilts. It's one of the advantages of running a country, intergeneration debt.

> The total tax burden is probably over 100%

Compared to what? income? capital gains? GDP?

total tax in UK through all taxes is 36.1% of GDP.

Taxes are not high in historical terms. USA for example had much higher tax rates (90% top income tax band) while it was arguably undergoing its phase of highest development.

Roads (and everything) get worse if governments do not invest in roads, or they invest in roads, but have outsourced to multiple layers of contractors who end up extracting a lot of the investment in profit and squeezing of labour costs and not in quality of road building.