Most jobs are meaningless, and it's hard to tell which ones are unless you think about what literal actions and materials are required to support human life instead of how much money is required to purchase those actions and materials.
Obviously we need the entire supply chain associated with food, shelter, power generation, water purification, clothing creation, medical supplies, border defense, application of the law, and a few others, but beyond those major supply chains- what do we as a society really need in order for everyone to remain alive for another day?
The question: if everyone who does what you do stopped showing up to work tomorrow, would anyone downstream of your job die after the workforce adjusted to your absence? If the answer is no, you almost certainly work a useless job.
"what do we as a society really need in order for everyone to remain alive for another day?"
We need everybody in that supply chain to work a full week to create the surplus that the rest of us live off.
Therefore the biggest problem is the answer to a simple question: "why exactly should those people work beyond Tuesday when they have all supplied themselves?".
As society improves its productivity we grow ever more dependent upon a shrinking set of highly skilled people working far longer than they strictly need to.
What are we actually offering them so they will continue to work longer?
I doubt "produce more adverts and PR" is the answer.
I agree with what you're saying, but why don't instead we all just work for the supply chain, and then we can all work two days per week, instead of worrying about how to incentivize those in the supply chain to work ever longer?
Because we don't have the skills. The necessary tasks are becoming more skilled, not less, as society progresses.
That's what defeats the old 'socially necessary labour' concept. Essentially few of us are good enough to do the jobs that need to be done, nor can we become good enough because we just don't have the talent.
Obviously we need the entire supply chain associated with food, shelter, power generation, water purification, clothing creation, medical supplies, border defense, application of the law, and a few others, but beyond those major supply chains- what do we as a society really need in order for everyone to remain alive for another day?
The question: if everyone who does what you do stopped showing up to work tomorrow, would anyone downstream of your job die after the workforce adjusted to your absence? If the answer is no, you almost certainly work a useless job.