It seems to me that to assume a 'universal' income must be "unconditional" is to restrict our thinking about a future economy. The economic system is an optimality problem: the standard for deciding among possible answers is 'which is best'. To arrive at the best solution we must consider as many possible solutions as we can. Here is my candidate for best solution to the problems associated with the existing economy: "Same Economy, Way Better Outcomes for Society."

It does not include an income that is universal in the sense that every citizen would be paid it, but it does involve an income that is universal in the sense that any (adult) citizen could become eligible for it. Having requirements for eligibility does make the income ‘conditional’. This change to the existing system would, however, make the existing economy self-regulating while eliminating unemployment, poverty, taxes, and public debt and increasing sustainability (with, to be clear, still no limit on income/wealth). Otherwise, there is little to recommend it.