Not voting, if you're otherwise able, is a tacit acceptance for how things are.

Presumably you don't want to vote for the incumbents, so vote for someone who'll replace them, whether you like that option or not.

Voting out a bad lot is the only legal way we have to protest.

And then vote third party next time if they don't change things to your liking. Then fourth. Fifth. Etc.

Don't like the political parties? Start one.

Think the whole lot should be lined up and shot? (For legal reasons this is purely metaphorical.) Start organising.

But if that's too much for you, vote.