Unfortunately deflation decreases the supply of capital but does not increase the supply of resources like food and such and does not decrease the demand for them. So it would not increase the true buying power the working class has. It would just disincentivize those with capital from investing in industry that could increase supply of food and such and instead people with excess capital will just hold on to their money.

The root of your concern is that the working classes buying power has been decreasing for decades which decreases their quality of life. The root cause of this issue is that supply has not been able to keep up with demand. The causes of this are large and varied depending on if we are talking about food, housing, or medicine etc. Inflation is one of the few tools the government has to cause industry to grow which will hopefully increase the supply of resources. Unfortunately there are many more factors in regards to supply and demand, and demand is increasing faster than supply.