What's the joke about regexes ?
'"I have this problem… I know I'll solve it with regular expressions." Now he as two problems.'
If the UK welfare system were half as complex as Australia's it would still be insanely complicated and almost certainly neither internally consistent nor externally with taxation, health, educational and training systems. In three words "an infernal mess."
Sir Peter has either swallowed the lemonade, or is unusually disingenuous even for a civil servant, in claiming adding Agentic AI to this shambles is going to reduce its problems; He will be fortunate if the added AI induced problems will be countable.
UBI in its purest form has the advantage of extreme simplicity not requiring anything much more complicated than a payroll system. Of course the detail devil has just been shoved over to the tax/revenue system which would also require reforming and simplification.
The greatest obstacles to any such program are neither practicality, nor entirely political, but rather people — their petty, unlovely unreasons - exactly those forces currently at work destroying the US.
So Sir Peter will have his way and your DWP will be fatally infected with AI and the infernal mess will blossom into a shambles that even the devil wouldn't own.