Accusations of whataboutism are invalid when you are calling out related points or highlighting hypocrisy and double standards:
https://en.wikipedia.org/wiki/Whataboutism#Criticism
Some commentators have defended the usage of whataboutism and tu quoque in certain contexts. Whataboutism can provide necessary context into whether or not a particular line of critique is relevant or fair. For instance, in international relations, behavior that may be imperfect by international standards may be quite good for a given geopolitical neighborhood, and deserves to be recognized as such.
Christian Christensen, Professor of Journalism in Stockholm, argues that the accusation of whataboutism is itself a form of tu quoque fallacy, as it dismisses criticisms of one's own behavior to focus instead on the actions of another, thus creating a double standard. Those who use whataboutism are not necessarily engaging in an empty or cynical deflection of responsibility: whataboutism can be a useful tool to expose contradictions, double standards, and hypocrisy.
Others have criticized the usage of accusations of whataboutism by American news outlets, arguing that the accusation whataboutism has been used to simply "deflect" criticisms of human rights abuses perpetrated by the United States or its allies. They argue that the usage of the term almost exclusively by American outlets is a double standard, and that moral accusations made by powerful countries are merely a pretext to punish their geopolitical rivals in the face of their own wrongdoing.
The scholars Kristen Ghodsee and Scott Sehon posit that mentioning the possible existence of victims of capitalism in popular discourse is often dismissed as 'whataboutism', which they describe as "a term implying that only atrocities perpetrated by communists merit attention." They also argue that such accusations of 'whataboutism' are invalid as the same arguments used against communism can also be used against capitalism.