The takeaway here is that candidate quality ultimately takes a backseat to the political circumstances of a given time.
This.
Also, to the extent that candidate quality mattered at all (very little probably, but in a 1-point race you never know what can make the difference), it seems quite clear to me that Ossoff did what few politicians seemed able to do and learn the right lessons from his defeat (don't run your whole campaign around "Orange Man Bad" and "I'm a safe moderate who appeals to The Suburbs

", but instead make sure to appeal to African-Americans and focus simple, easy-to-understand policy items that materially benefit people). So in this sense Ossoff's defeat then was exactly what he needed.