Black-ish is a sitcom about an upper-middle class family living in a predominantly white neighbourhood. It manages to be entertaining and funny while at the same time bringing to light the many issues facing black people today.
Some characters are over the top, but that is sitcom television. For every moment that you cringe at someone's behaviour, there is another that makes you loves them.
There does tend to be a few episodes each season where more serious topics are covered. Bringing up difficult or uncomfortable topics should happen more and Black-ish has brought black issues to prime time and that is fantastic.