The AFL-CIO was a major component of the New Deal Coalition that dominated politics into the mid-1960s. Although it has lost membership, finances, and political clout since 1970, it remains a major player on the liberal side of national politics, with a great deal of activity in lobbying, coordinating with other liberal organizations, fund-raising, and recruiting and supporting candidates around the country.
If you haven't heard anything from them it's because you haven't been listening. They are very active on workers rights.
And there's two sides to the coin. Why should you benefit from their hard work campaigning for higher wages without contributing to the fight? Read up a little bit about the history of the American Work pre-Unions. What was the phrase? Nasty, brutish and short.