My solution for pensions is as follows.
Starting April 2027, every newborn is given a years tax-free allowance ie £12570 and is placed inside a SIPP 100% in equities. The trade-off is that there will be no state pension for that person. The tax-free allowance will rise year on year by inflation.
You would be able to change providers if you so wish but obviously, the money would not be available until state retirement age ie 67. I would keep that set forever. When the time comes, you would only be able to buy an annuity.
If you never put a single penny into that pension, 5% growth (low for the stock market) over 67 years will net you just under £354,000. Buying an annuity with that would give a lump sum of £87,500 and annual payment for life of £19,600
10% growth over 67 years (about average) will net you just under £9,800,000. Buying an annuity with that would give a lump sum of £2,450,000 and annual payment for life of £549,000.
If you add just £50 a month for those 67 years, the figures are phenomenal. You would have a pot of £14,600,000. An annuity with that would give a lump sum of £3,650,000 and an annual for life payment of £818,000.
I would add a proviso that you have to pay back whatever the seed money is the year you retire out of your tax-free lump sum.
State pension costs would fall every year until, after 67 years, they are self-funding and cost the country nothing.
I'm sure there are flaws in my plan but it seems simple enough to me.