Since not voting is a valid and intended choice in most democracies, I dont see how "just" not voting does not support the system as well.

When I vote I am way more invested into what the poeple / parties I voted for do and sometimes even feel the need to defend them in social media. I also feel like I have to inform myself before an election about the choices that get presented to me. So not voting (myself) actually improved my life a little.

One idea I personally like is to actively break the rules and enable people that are not allowed to vote by giving them your vote-by-mail ballot.