Boosting aggregate demand will not solve the unemployment issue when you consider that one person with automation can produce enough goods to satisfy the demand more than one person.
But redistributing money to people on the bottom to give them safety nets (and allow them to do things like re-educate themselves for some other career) as well as spend it back into the economy is a way to keep them from going completely bankrupt. When a company goes bankrupt, it's one thing. When a human does, it often results in starvation and homelessness.