I think arguing that supportive care is grossly suboptimal is going to be a pretty difficult take to sustain, given that a huge majority of the infected manage a full recovery from SARS-CoV-2 with no treatment at all. This complicates the cost-benefit outlook for any early treatment; it would be entirely wasted on those patients, while the potential for severe side effects (as seen also, e.g. from HCQ) would remain.