Most interest in politics is IMO similar to interest in sports or movies. It's fun, and it offers an opportunity to show off a bit, gives something to talk and socialize about, helps people form communities and define their interests. But beyond these kinds of social goals, there is no true value.

I'm not totally sure what you mean by this. With that said, it does matter very much how the government distributes its resources. While the government is admittedly inefficient, that doesn't mean that it can't be improved. Since politics determines how those resources are distributed, wouldn't becoming involved in politics be a valid and important way to gain your favored causes-i.e. existential risk mitigation- support? Declaring one method of gaining support to be automatically invalid, no matter the circumstances, won't help you.