With your higher income, you can realistically save for a house deposit, or other genuinely high value items.
You can look at investing in yourself by taking expensive courses which will increase your employability or earning potential.
You probably have a decent credit record and access to funds most genuinely poor people can never dream of achieving.
When you are on a very low income, the things you can aspire to are items you might not value like a pair of trainers, because you as a higher earner can aim for things that they can never afford.
What would be the point of saving for years to get that much and have all the hassle of monthly proving how much you have in savings, with the threat that if you spend enough to drop below that amount of savings you can be accused of intentionally depriving yourself of capital in order to claim benefits when it's still never going to be enough to use as a deposit on a one bedroomed flat?
Aspiration for lower earners stuck in the poverty trap is punished in the UK unless you have the money/earning potential to blast past that £16,000 point, and the punishment begins at £6,000 when you start losing Universal credit so why struggle to even get that far so it can become harder?
Benefits are set up in this country to stop people being able to get away from them easily.
Most cannot even get to the point of saving £6,000 but they all know that they will lose help if they get that far.
Why not buy a pair of trainers today to make you feel good when you will never save enough in your whole life to pay what some people spend on a big holiday?
Why not get that car on finance when they couldn't afford the repairs on a cheaper car if it broke and they need a car for work?
When saving is punished, spending seems more reasonable and nobody chooses misery over happiness, however fleeting the happiness may be.