Ask HN: Spectre/Meltdown do I need to replace my phone?

In light of recent events, everyone is talking now about how critical it is to immediately update their OS, update their browsers, update their kernel... But almost every smart phone in the world will never get any system updates. Are we all supposed to go out and buy brand new ones from the select few that are still getting security updates? Is there any future for using this as some kind of legal leverage against Google and mobile manufacturers?