A lot of the idealists are going to give you shit for holding this position. They have their reasons, and some of them might even be good ones, but let's skip that for now. If you're a realist or a pragmatist, their idealism probably isn't going to do much for you. And I get where you're coming from. Here in the US, we have a large number of disenfranchised voters who feel exactly the same way as you. And the Powers That Be really like it that way, since less voters means less work buying elections.
On the plus side, votes do seem to count. If you look at the ridiculous amounts of money being spent in US politics on campaigns, that should be prime evidence of the power of the vote. The problem, of course, is in who holds that power. Voters cast their votes for a great many reasons, and some of those reasons have been fairly easy to subvert.
The cure for this problem is not simple, and it is not easy, and I don't blame you for not wanting to help. A great many good people will likely need to stand up and serve jail time and worse in acts of civil disobedience to try and change things. Getting people to stand up and take notice to what is going on around them, and not just passively tune out discussions of politics and social justice will be a major challenge by itself. Getting people to believe in change, and to believe in a better way of social governance, and actively participate in politics... that does seem pretty impossible. And if that dream were to ever come true, and we did 'fix' things, it would carry with it a good of different problems.
But I have some good news. It only feels like there is nothing you can do about it. The bad news is that there are powerful forces at work trying to make sure you always feel that way. Of course, it has pretty much always been up to you how you want to feel about that, and what you want to do about that. Rather than passively accepting that things suck and committing yourself to the belief that it will never change, even something simple like trying to engage people in discussions on political issues can help. The more minds like yours that we can even open to the possibility of change can only help.
Of course, change is not without risk, and getting your hopes up is a good way to see them dashed to pieces at your feet. But, you already know how it is. This is the real world.