It does happen, I know of a relative who claimed all her life and worked cash in hand, had a kid who also then went straight into having kids and claiming benefits including full rent paid - then had the audacity to complain when the landlord sold up and she was going to have to move 1.5 miles up the road as she didn’t want to live in that area. The child now works the bare minimum and claims the maximum she can - she is lazy and entitled.
The initial relative mentioned lives alone in a 3 bed, full pension, full pension credits, reduced council tax and still works cash in hand. My mum gets only state pension despite having worked all her life and having a disabled child that she still cares for.
Thats one set of relatives, I am aware of another relative that has never worked and has children and gets everything paid for, still manages a holiday. Another relative that has managed to get housing association even with 2 full time incomes coming into the house that are decent wages. That person has gone into a private rental and kept their name on the books and a single childless working age relative has gone into the house despite no entitlement and other families desperately needing it.
So as a PP has said, the 2% of fraud is what what authorities know of, but we’ve both been able to name a good few that have “slipped through the cracks”.
What these do is bleed a system set up for people that need it, and add to the overall welfare costs.
Welfare is there for people that need it and have no other option.
Ironically when I was out of work following redundancy (for 6 weeks) I needed support and was put through the wringer. I had paid tax and national insurance for 20 years prior. Was told I should take my children out of nursery to save money as I wasn’t working though I needed them in childcare so I could look for work, go to interviews and ensure they had a childcare slot when I got back to work. I finally managed to get job seekers allowance (which they concealed even existed) which I claimed for about 4 weeks, got a new job and went back to work full time.