"valuable goals" break down in a lot of different types but the key difference here is: If you work toward the valuable goal of keeping people from starving, and you do some work but don't fix the problem, at least you've fed SOME concrete people. If you work toward creating a political ideology and fail, you've done nothing of any use to anybody. Politics, like celebrity and sports are zero sum, the more famous you are the LESS famous someone else is. There are already millions of people working to achieve fame and power through politics, and importantly, they want to do it at your expense, they want you not to have that power. This means that unless you have large leverage on politics, the time you spend on it will simply be wasted.