Wages, like prices, rise and fall on demand, simply because wages are just another price, in this case the price of labor. When there are more workers wanting jobs than available jobs, the price, or wage, drops. Likewise, when demand for a skill drops, so does the wage. At one time, for just one example, a skilled blacksmith could make a good living. How many can do so today? Same with buggy whip makers. OTOH, when there are more available jobs than qualified job seekers, the price, or wage, goes up and the MW doesn't even enter the equation. We're seeing that now, and wages will have to rise higher than what people can get from the taxpayers for doing nothing in order to fill the jobs.
The bottom line is, producers charge prices high enough to cover their costs and provide a profit. When their costs rise, prices do too, and labor is one of those costs. If wages are not rising, look to the causes. Do the jobs require a particular skill set? If not, the wages will not be high. Is the job in an industry that's dying out? People who understand how VHS tapes work or are very good at renting them won't get paid much. I'm in IT, and if I still had only my original skill set, I would have maybe a handful of companies that might hire me, but not many. I've had to constantly re-invent myself to stay current. That's just the way it works. Why should someone expect to get paid the same when they walk in off the street as someone who's been on the job more than a decade?