those are some loooooong odds .
Sigh. What odds are there of a cash ISA returning more than a paltry 0.9-1% ish return? A big fat zero. So holding a decent chunk of bonds will give similar returns (1.4% notionally) but have the long shot upside of a much better return. Plus it’s a bit of fun – you don’t feel like you’ve won when you get a monthly interest payment, but do with PBs.
They’re a suitable component for a balanced savings portfolio, nothing more, nothing less. Some regular savings products, some PBs, some stocks, shares and funds, a bit of gold and some leftovers for offshore money laundering operations (does buying bike bits in Germany count?)