It's not the same system, they're quite different. It is non-prescriptive, so it has less potential for bureaucratic waste than a means-tested system that is

It's not the same system, they're quite different. It is non-prescriptive, so it has less potential for bureaucratic waste than a means-tested system that is prescriptive about where the funds go, or worse yet explicitly spends the funds on specific publicly run programs that may or may not be efficiently ran and may or may not be what poor people need. Also, the marginal tax rate gradient under negative tax is gradual instead of a cliff (which is usually the case in means tested systems) which helps to avoid the disincentive problem.