These are conservatives we're talking about. That's the beginning and end of their logic.
The figleaf is the usual trickle down "tax cuts will boost the economy, rising tide all boats, yada yada" nonsense that has been resoundingly discredited for decades. It doesn't matter. The tories don't care because they know they're just doing this to make rich people richer at the expense of poor people, and their voters don't care because they'll believe anything if it means fucking over immigrants.
You'd be surprised at how many people in the UK demonise foreigners and benefit claimants. Sunak has basically done nothing outside of support populism, so this is just a grab to try to get both conservatives that want lower taxes, and flag-shaggers that love Brexit, hate foreigners and freeloaders, etc.
If you fall on hard times and need the help and support of your community you're weak and unproductive and should be disposed of so someone more productive can move in to your domicile unit and pick up where you left off. It's just good business.
Please stop thinking and get back to work. Don't forget, it's Hawaiian shirt day on Friday!
It's class war. Plain and simple. The rich have been fighting a class war on everybody else and a lot of people unfortunately seen to enjoy being fleeced.