Everanewbie I presume your figures for the number of "millionaire" pensioners comes from this
https://www.if.org.uk/wp-content/uploads/2022/06/pensionermillionairess_FINAL.pdf
Or something similar.
So: there are roughly 3 million pension age people in the uk in households with total assets of over 1 million. The figures are misleading in that they are for households (most of which have more than one person) and include all assets- in the southeast houses are worth £££££ as we all know- but that is only valid when it is sold.
This is in stark contrast to the increasing number of pensioners living in abject poverty:
"The report also details that the average annual income of the poorest 20% of retired individuals is below the minimum amount needed to live on. This means that the country’s poorest retirees, including those solely reliant on the state pension, have an annual income estimated to leave just £41 for a weekly food shop and insufficient funds to run their own car or service their boiler.
Relative pensioner poverty is at one of its highest rates (almost 18%) this century and is more than four percentage points higher than a decade ago. It means that 2.1 million pensioners in the UK have an income that is less than 60% of the national average."
ageing-better.org.uk/news/50-years-progress-against-pensioner-poverty-under-threat-state-ageing
So- while some pensioners are comfortably off, 20% have less than the minimum amount needed to live on. In one of the richest countries in the world, 20% can't afford to live.
Pensions are already taxable for those with an income higher than the personal allowance btw, a fact often overlooked.