During the pandemic I stayed in a B and B, about £400 month, no bills, just buy your food, so you could live in the UK for about £700 a month easily. Not a great life but a liveable one.
I currently only get £650 a month private company 55 year pension, but can live in Thailand as I rent my house out outside London for a silly amount (silly but still 25% below market value). So, if I take my house back - no mortgage - I could probably live a life there now, not great but OK, Get a lodger in for 400-500 a month and my life in UK now would be fine.
At 65 my income for pension would be about £1,400 a month - and with the house paid, I'd live quite easy in the UK - bung in a lodger and that £2,000 with a house would be a great life.
This article above should be asking how many people wasted their money, sold their house and assets and now do not have a pot to wee in on return to the UK and would their meagre income now from wasting their life's money now give them a life !
I planned my retirement and old age, I will not be rich, but OK.
As for the amounts quoted in the above article for £4,000 a month plus to live - total bull - unless you are renting a flaming mansion !