What you said was, "People put money into their own pensions so they can be better off in retirement, not so that the government can punish them by reducing the value of their state pension". As the government has not been punishing people by that, you'll forgive me for thinking you were claiming it as historic fact.
Unless you know different, the pension has increased relative to earnings (to 30.2%). But you don't want to pay the higher tax to keep that going. See the IFS: "increasing the state pension to be at 33% of average earnings in 2050 would cost an additional £15 billion per year in today’s terms (about 0.5% of national income), compared with keeping the state pension at its current share of average earnings". And see this: "Retaining the triple lock while raising the state pension age would hit poorer people more because the loss of a year of state pension income is more important for those with lower life expectancy (which poorer people tend to have), as they spend fewer years above the state pension age. On the other hand,
those with a higher life expectancy benefit relatively more from the triple lock, as they are more likely to be receiving a generously indexed state pension in their 90s and beyond."