The problem is not pensioners ( we have one of the poorest pensions in Europe) and a much higher age when we can take it than some other countries eg most women in China retire at 55! ( only managers wait to 60). People in the poorest areas of the UK suffer from ill health and die about 10 years earlier than the people in the richest areas.
The problem is not people on UC, nor the disabled, nor immigrants who desperately want to work, nor asylum seekers who also want to work but aren't allowed to (unlike in many other countries like Spain. ) It makes no sense to have people trapped for years unable to work, particularly if they have skills we desperately need like nursing. Particularly as we have a desperately low birth rate which without immigrants shoring us up would lead to total disaster.
The bigger problem is that the super rich have been given many ways to avoid paying their share. ( We are one of the richest countries in the World.) Off shoring profits eg. putting their money where income tax or investment taxes are low or non existent etc. while Companies such as Amazon pay poverty wages. If wages were increased it would be a boost for the economy as people ( especially the poorest ones ) would spend it here.
The 50 richest families in the UK have the same wealth as the poorest 50% of the population, 30,000,000 people. We should be taxing their wealth. A mere 2% or even more would barely be noticed by these billionaires but would pay for our NHS, free dentistry, Nationalisation of Water, Rail, Mail etc. so we can all benefit. It makes no sense to allow the profits from these industries to be taken out of the UK to France, Germany, the US etc. when we need the investment here.