Whataboutism can provide necessary context into whether or not a particular line of critique is relevant or fair, and behavior that may be imperfect by international standards may be appropriate in a given geopolitical neighbourhood.[8] Accusing an interlocutor of whataboutism can also in itself be manipulative and serve the motive of discrediting, as critical talking points can be used selectively and purposefully even as the starting point of the conversation (cf. agenda setting, framing, framing effect, priming, cherry picking).

From the article.

I'm pointing out that one of your precious democracies is locking up pensioners for their speech, providing context into whether critiques of censorship are relevant or fair. Either you can condemn the UK as not being a democracy to be consistent, or you can admit that democracies can restrict speech. Pick one, instead of just selectively disregarding the critique.