Eh, for most people it's simpler to just use a cash ISA which can provide almost the same rates. Most people don't want or need to carry a huge cash float as opposed to other kinds of investment.
Well, yes, but after maximizing an ISA that's still an option. Also the government is clamping down on cash ISA.
That only works if the capital is already in an ISA or you want to invest less than £20k (soon to be 12k) though. It is common to use gilts to build a gilt ladder to have some level of guaranteed income for older/retired people. This allows you to build your own cheap annuity.