First those developers don't get any money for their work, now you also telling them that the work they are doing isn't really valuable anyway?
Did you consider the fact that half of your examples of worthy things are using the unworthy log4j?
Did you consider the fact that half of your examples of worthy things are using the unworthy log4j?
This is how the value is measured.
But if you take a much harder task, like building a performant and safe JIT language runtime like the OpenJDK, you'll see that even in the open source model, people can't actually deliver it effectively for free. It often starts out from a company that later open sourced it, or it's backed by academia, and contributions require deep expertise, so sometimes companies had to have their own staff contribute to it on their own payroll.