Not necessarily. I view the advertising industry as a net loss to society, yet the amount of revenue is immense and the salaries of the people working there are equally large.

Yes, the idea of exposing potential consumers and informing them of what your product is in principle fine, but that idea was perverted long before any of us were born. Now it's about spending money on selling products that aren't selling themselves, because it's cheaper than making a better product. As always, exceptions exist.

Are you measuring a persons worth based on their income?

OP wrote: "I would have been far more qualitatively useful to society at large." There are far more people that need UI work (in the form of websites, apps, etc) these days than art. UI work scales very well, art not really - you can affect way more people and that is reflected in the salary.

"Qualitatively" UI work is far more useful to society.

There's absolutely no basis for a judgement like that without introducing assumptions about what's valuable and what's not.

Earning money is not easy. The fact that on average a larger group is willing to pay for UI work than for art indicates that UI affects their lives more than art and is more worth to them. Whatever one's reason is.

Let's go with "valuable is something that improves your life" or "improves your wellbeing"

That doesn't really work. Is my life better or worse if I feel worse about myself because I become aware of the way that I'm part of a unethical social system? Given the choice, I wouldn't choose to be a happy person who lives in the Jim Crow south and supports segregation. Part of what many artists do is help people understand themselves differently. You can't assume people are going to be willing to pay for something that's good for them (by their own standards).

My skills are now very bounded to building interfaces for consumption, not critical thought. In fact, the choices I make for developing interfaces usually revolve around the user being some level of drunk.

My senior thesis was a receipt printer that wireshark'd instant messenger messages on our school's unsecured wifi and dumped those messages into a pile.

...so you are not critically thinking about your work in the context of how useful it is to the end user? That's a bad UI work, I'd say.

As for your senior thesis - Developer's job is to create software that makes lives easier. It was your decision to use your skills to harm people by exploiting their privacy. Or it could be seen as something good - you discovered a way to exploit people and if you informed whoever was running this app you helped a good amount of people in your school.

I think you're misunderstanding both my role as a UI developer and as an artist...

It takes critical time and energy to reduce the complexity of a products' features to something a layperson can use, and a layperson is usually barely paying attention.

As to your second point, I wasn't a developer, I was an artist, attempting to ask real questions about privacy and spark real discussions and possibly getting myself in trouble to start a conversation.

Would society be better off if Linux kernel developers stuck to doing things that paid?

How many people work full time ubpaid on the Linux kernel? For the 4.15 kernel, AMD, Intel, Google and Red Hat contributed between 35 and 50% of the changes, depending on whether you count number of commits or number of lines changed.

How long did linux exist before there was a corporate sponsored person working on the kernel?

Only half rhetorical, as I'm actually curious.

Maybe, if you extend that to free software in general. It's interesting to think about.

I think you're equating 'society' with 'the market' here.

I think you may be picking up on a but of a cultural difference here. In America, people are identified, both by themselves and by others, in a large part by there job. It's a huge part of personal and cultural/societal identity.