If the state benefits are that poor, why are people coming here? Anyway the easy way to cut benefits is to time-limit them. For example they could limit unemployment benefit to 12 months. Another way would be to severely limit benefits paid to non-citizens (e.g. illegal immigrants). Another way would be to put the responsibility on relatives. And so on.
More positively they could cut benefits by needing to pay out fewer benefits. For example, if parents could use the personal allowances of their children then there would be less need for child benefit. If you allow children to use the remainders of their parents' personal allowances then you encourage elderly parents to move in with their children.
People are coming here to work and contribute to the economy.
It's just the Tories have taken to
spending money, holing them up in purgatory and making them a PR win to sell to the weak minded.