I think the idea of retiring in your 50s is faintly ludicrous tbh. Way to make yourself older!
Why would retiring in your fifties make you older? I am nearly 60, been retired almost 2yrs, and feel younger, fitter, more energy that I ever did working! I have a Labrador who gets lots of walks, we have a motorhome that I can go off in alone (DH is still working, but I actually have better pension provision than him). I am never bored and love life without the constraints of work.
I know quite a few people of my age and younger who have retired in last 5yrs or so, so generally mid 50s upwards - a lot of them are women, and have better pensions than their partners. There are still many people that have final salary pensions (only one that I know is public sector, others are private), some of which pay out at 55, or at 60 and they cover intermediate years with savings. One of my colleagues finished just before me, at 52! He had been planning his retirement since his 20s.
As per @HyacinthBridgerton dad, none of us made major financial decisions, but we all bought houses young, none are divorced, all worked after DC and most have lost their parents so had some inheritance (mine was quite small but has helped).
I have no plans to go back to work, whatever Rishi or Jeremy tell me to do.
I don’t, however, know anyone with GC in their fifties, most of my friends have children still in their early/mid twenties.