Recent figures show that the cost of living has risen more steeply for pensioners than any other group. They haven't benefited from the drop in oil prices, because they buy less petrol.
If you've given up driving, you rely on public transport and are hit by fare increases. (It would cost me over £10 to get from the suburbs to central London without my Freedom Pass.) To get to the shops, or the station, it's 2 buses. Pensioners often can't walk as far as younger people, particularly with shopping.
If you're at home all day, your heating bills are obviously higher.
Pensioners are on a fixed income. Many have relied on income from savings to pay big bills, like house maintenance, insurance etc. This income has dropped dramatically because of low interest rates. Dentistry is a major expense when your teeth start falling out, and there are no pensioner discounts.
Only the very poorest pensioners get benefits. There are very few rich pensioners. The vast majority in the middle would certainly notice if their benefits were taken away.
I agree with universal benefits and am against the changes in child benefit. But at least you have a choice about increasing your family. There's no choice about getting old.