You're answering my question by asking me a question. I think it's perfectly reasonable to ask you to explain how UBI results in a redistribution of wealth, as I don't see how it does.
In terms of the current system "not working", it is easy to say that the system "isn't working" but to say that something "isn't working" you've got to define what success is, i.e. "what good looks like" and i find that those that argue that the current system isn't working have a very confused list of success items. For example, eradication of poverty. The reality is that real poverty as it used to be known in this country has effectively been eradicated. They've had to change the definition of poverty in order to monitor life at the bottom end of society and so we have new metrics such as "in-work poverty". You could have a family in the UK where both parents work, run a car, rent reasonable accommodation, have food on the table and sky TV and they are part of the poverty statistics in this country. The idea that most people in the UK that are classed as living in poverty ARE actually living in poverty would probably be seen as some sort of sick joke by someone in a slum in Mumbai for example.
So is the goal of the "system" to enable even those at the bottom to live a comfortable existence? You then need to define what that existence looks like, I.e. what standard of living is it acceptable to ask other people to pay for (which is a question of the current benefits system and will remain a question in setting the payout threshold in any UBI system).
What tends to happen with people that believe the current system isn't working is that you then get this success factor thrown in of "equality". Which is basically saying that the goal of the system should be to ensure equality. It usually involves varying degrees of taking wealth off of those that have accumulated it to give to people that didn't manage to. To be honest this already happens to quite a significant extent in the current system. In fact, changes to tax thresholds have meant that vast swathes of the work force have recently been taken out of income tax liability altogether and well over 50% of the UK government's tax-take currently comes from a tiny selection of wealthy individuals and large corporates. Ironically this also gives those individuals and corporates the kind of significant lobbying power and policy influence that those that advocate for "fair/progressive" taxation find infuriating....