A couple of points worth remembering:
A huge number of those in receipt of a State “pension” do not receive a pension at all. They receive State support in the same way as they would if they were of working age, having made little or no contribution to their “pension pot”. Ironically those “pensioners” usually receive far more in cash and sundry benefits than do genuine pensioners who have made all the required contributions.
The sundry benefits (winter fuel allowance, free travel, etc.) are simply fringe benefits of the State pension system - part of the package for which those who have contributed have paid and no different to, say, free or cheap health insurance which some people receive from a private pension providers.
The State pension scheme, apart from having to support those who have not made the required contributions, makes current payments from current contributions - a giant Ponzi scheme, in fact. The true pension payments (including sundry fringe benefits) should be made from investments of funds made by pensioners during their working life.
As for “The world's poor need the money. Pensioners don't need this subsidy” the government (or more importantly the electorate) needs to decide what it is paying tax and NI for. It is dishonest to take money from people who expect it to be used for their retirement only later to say it is to be given to “the worlds poor” because they need it more. Pensions are not about need, they are about contributions made for funds later paid.
There needs to be a clear difference made between genuine State pensions and other retirement age benefits which have not been funded by the recipients. Genuine pensions and fringe benefits can then be made on the basis of contribution, not need. The country can then decide whether it wants to spend its general taxation on unfunded retirement age benefits for the UK's "poor" or supporting the poor of the rest of the world..