Your premise is that some worker’s labor is more valuable than others’, as an inherent or essential attribute of the activity representing the labor.

Literally not the point I was making. If your objective is to incentivize employees to be productive and achieve some kind of monetary objective which, because of the default state of even the most populist of countries, most people need to maintain their desired standard of living, then you should pay people different amounts of money based on how well they support those objectives (and practically to overcome market forces based on how many people are willing to provide those skills you need).

yes, some people based on some combination of experience and acuity are able to churn out 10 widgets and hour instead of 5. If you are an employer that profits from selling widgets and needs to pay people to make them, and you prefer people make an effort to increase this thing that you want them to do, you should incentivise that behavior in some way. I’m not saying you should exploit people, there is some minimum amount of compensation that allows people to survive with a reasonable minimum standard of living based on the prevailing societal norms of where you live. Anthing less is not humane.

Value is not an objective attribute.

The amount of money you pay people and the amount of money your customers pay you is a very objective and generally accepted definition of value. Coincidentally, it’s also the definition of value that the original premise is using

The real number I’d like to know is how much value my labor is actually producing versus what they pay me.

They’re talking about their pay, which is a concrete number, and comparing it to the value they are producing which, based on context clues, heavily implies they are talking about monetary value. You can’t really pay someone commensurate to the emotional or utilitarian value they produce without first converting it into something monetary.

Your objection about the plumber is a red herring.

Activities that are not productive are not relevant to a discussion over how various activities of labor are valorized, because labor is simply productive activity.

It was a bit hyperbolic, but you could easily say a plumber that makes a fix that breaks in a week provides some amount of value, you get running water for a week where you would otherwise not. No matter how you wish to quantify monetary value, that is clearly worth less than a plumber who will fix you faucet so it runs for 10 years.

Your conception of some workers being more or less removed from a product is simply a subjective feeling, irrelevant to the value of the worker’s labor provided to the social processes of production within the enterprise.

No, my whole point originally is its based on how difficult it is to quantify the monetary value (the kind the original question was about) for some roles compared to others. Literally no one would say that the IT professional that ensures that sales people are able to send out emails and track sales isn’t not essential to the objective of creating monetary value by selling something to someone, but at the same time without a sales person going out and convincing people to buy a product you’re not going to get a lot of sales either. So who is ultimately responsible for the sale? Both. What fraction is due to the IT professional and what fraction is due to the sales person who does a good job understanding the customer’s needs and making a convincing argument for why you should buy the widget? That question is very difficult. Most jobs instead are built around “how do I maximize my personal profit” which is usually what people who run companies care about which brings us back to the original concern that companies will try to pay you the very least amount they are able to while still incentivizing you to do the job well enough that you provide as much net positive value to them while minimizing how much they pay you.

As far as workers being more or less removed from the product, the reason it feels easier to apply this value to a sales person is because they can clearly show they made X sales calls and garnered $Y worth of revenue or net profit to the company. So, if you really wanted to figure out the direct monetary value of the earnings brought to the company by the IT professional, you would essentially need to work out how much of the pie that the sales person brought in was due to the IT pro supporting their needs and then do this for every other role that they IT professional helps and connect those roles back to the ultimate amount of profit they generate for the company (aka value in the context of this discussion).

If you are going to pay people in something with monetary value, which most people living in most extant economic systems that have been implemented to any non-trivial degree, then you need to somehow come up with a number for what to pay this person if you want them to show up to work and perform the function you intend of them.

Final note,

You can’t just declare a definition of a word to be something completely removed from the way it is used relating to the topic being discussed then act like a point you make relating to this other definition you are choosing to use is somehow valid in the context of the original discussion.