And it is a decent pension unlike the UK pension which is the worst. In Europe despite being one of , if not, the richest country
But the basic pension doesn't include all the other stuff handed out on a plate like housing and heating.
People who didn't take a penny in benefits generally have some sort of private pension to afford them some sort of standard of living. Although if you worked as a teacher they tax that pension as income 
All private pensions are taxed as income, as soon as you are over the zero threshold its tax as normal (and the state pension counts towards that).
Unless they were invested post tax. In which case you only pay capital gains. AIUI.
A pension is a kind of tax wrapper. They are usually set up as a kind of trust fund, and as such the 'owner' of the pension doesn't actually 'own' the investments within the pension, although they are reserved for the eventual benefit of the 'owner'. It's subtle, but that's why a pension fund is not counted as an asset in bankruptcy or liable for death duties/taxes - because the 'owner' doesn't actually 'own' it at all.
An asset within a pension fund is generally free grow (or fall) free of all taxes - whether that be Capital Gains, Corporation tax, Dividend tax, whatever.
Not sure how you expect to pay CGT on an asset owned by a pension fund though. If you're calling a Buy To Let your 'pension', then yes you may well pay CGT on the BTL when you come to sell, but it's not really a pension in the true legal meaning of the word. If you die, it'll be liable for death duties. If you sell you'll pay CGT on any profit.
All cash income from a ALL pensions is liable to income tax - doesn't matter if its state pension, public pension, private pension or workplace pension. The state pension is usually paid 'tax free' because it is (usually) less than the personal allowance (£12700 at the moment). However, once your total income, including all pension income, exceeds your personal allowance then you will pay tax on any amounts above the personal allowance.