You need to look at everything, i.e. what other benefits they UC claimant gets, free childcare, etc
I've just done some number crunching.
Total benefits for that person would be around £2.7k per month plus their net wages which would be £1.5k so total £4.2k.
Net wages on £130k would be £5.4k per month.
So working their arse off, not only in a job paying £130k but also in the education and training to get themselves there, to come out with only £1k more than someone basically on not much more than minimum wage.