When productivity goes up, that doesnt mean workers are making 10X as many houses or hamburgers, which capitalist are eating.
For me, this begs the questions of what exactly is being produced when we say worker productivity has increased, and where is it going? If it is "stuff" being produced, surely it should be evident somewhere, like massive exports hoarded stockpiles. Alternatively, the productivity is an illusion because there is a corresponding inefficiency or deadweight loss, like paying some service workers to create problems and paying others to fix them.