You ask how we should decide what jobs has "value" and which hasn't. Well, if it isn't obvious that a job has "value" then perhaps it has no value?
I’m not being difficult here, these are tough questions.
Allowing the market to decide value is the option we currently have, and seems to be the fairest so far.
I am sure that it is not optimal, and it has flaws, but no one has yet convinced me that there is a better model.
This presents a workless society as a real thing, rather than a hypothetical. I might be wrong, but I’m not aware of any workless society (apart from hunter gatherer tribes and history). If you have examples of a society that functions fully without work, then please share, I’d be interested to see how you solve volunteering for unpleasant or undesirable tasks that no-one wants.
Society decides which tasks have value and which don’t by whether consumers spend money on the work product produced by those tasks.
Now, society’s way of working this out isn’t perfect, but how else should we determine which jobs are adding value and which are not?