Worker A should be paid a wage that allows him, or her to be able to afford food, a place to live, adequate health care, and all the same things a scientist working to find a cure for covid 19 would. What should we pay that same scientist who works relentlessly for years to develop a vaccine, and he never figures it out? Well I believe he/she should still get paid enough to have food, a place to live, and adequate healthcare like the guy digging holes, and then filling them back up even though he didn't produce a damn thing. Lets switch it around a little. Let's say worker A had gone to college to become a research scientist in the field of virology. He would be a great candidate for helping to find a vaccine for covid 19, but in the Capitalist world in which he lived his education has put him in deep debt. He now has to go did holes and fill them back up in order to pay for something society should have paid for in the first place for the betterment of the whole. In a Democratic Socialist society the guy digging the hole was digging it to support the community, which also supports the scientists efforts, and would have helped by his labor in paying for the pursuit of the scientists interests.
Real scientists do their work following their interests, and the needs of their communities, not for a higher pay check.
Fuck capitalism! Capitalism/money worship is truly the root of all evil. It satisfies greed at the expense of other people's lives, and the planet's health. When worker A stops digging the holes, nobody is going to be doing anything. That makes his labor worth allot.