whataboutism is a debate tactic. Your only answer should be "that's a different issue, I'm talking about [original_topic]". Entertaining the whataboutism shifts the conversation to basically a strawman debate where your opponent will win, without ever having to address your original point. It's absurd logic when you think about it.

Black people not being prosecuted for crimes -> White people commit mass shootings therefore its fine for black people to commit crimes

Pedos and Predators operating freely amongst the Alphabet Mafia -> the catholic church rapes boys therefore the alphabet pedos are not a problem.

etc etc