I'm starting to think we do need something so fundamental like this to actually effect the change we need. Both cheeks of the same arse will just continue to fart around the periphery re-arranging deck chairs on the Titanic without making the necessary changes we need.
I never used to like the UBI idea, and still don't really, but I'm definitely coming to see it as the best of a bad job to get things changed.
The problem, though, is what level to set it at. Obviously, alongside it, we'd need to zeroise tax free allowances so that people paid tax on the first penny of extra income, whether wages or savings or property rental, and probably set the rate of tax at a pretty high level, maybe even as high as a straight 50% across all income levels. The tax rate has to be high to pay for everyone getting UBI. So, maybe each individual gets £15k UBI, but then pays 50% flat rate tax on all other income, so if they also had a job paying £50k p.a. their total net income would be £40k (£15k ubi plus 50% net wages on £50k of £25k). Having a maximum tax rate of 50% would certainly make working/earning more an attractive option, without being a punitively high rate. (Someone currently earning £50k p.a. would pay around £10k tax/nic, so net wages would be a similar £40k).
Another problem is that for UBI to work, it would have to be flat rate for all. No "extras" for different circumstances, i.e. it would have to cover housing costs, prescriptions, council tax, bus fares, etc - the moment we start "add ons" for different circumstances, the UBI philosophy falls apart and we're back to square one. Disability benefit "add ons" would be a particular problem that needs resolving, as in theory UBI should be fixed regardless of disabilities/needs with no extra payments based on disability, so to get around that issue, where some disabled people clearly have extra needs that cost money, we'd probably have to move to a care system where the "extras" needed such as carers, special equipment/supplies, extra housing costs, patient transport etc are paid directly from the NHS/care budget and provided free to the person, so they don't need extra benefits on top of UBI - this is the biggest problem in my opinion.