Every system has its own set of drawbacks. A non-voluntary system has the drawback of forcefully extorting money from people with proven capability[1] and then

Every system has its own set of drawbacks. A non-voluntary system has the drawback of forcefully extorting money from people with proven capability[1] and then handing it over to possibly incapable / lazy people. [1]: Assuming an uncorrupted system. Else, all systems are equally bad.