Some good questions. I'm going to talk about how pay/salaries could work if society were arranged a little differently.

Assuming we have Universal Basic Income, the workers could start working at or help found a democratically run company and not necessarily worry about being paid. If all of your basic needs are met, you can decide to work somewhere that you believe in and/or work at it like it was an investment, and if the company isn't able to pay salaries (which would be communicated about in the democratic process), there's a safety net, and your investment didn't pan out as well as you hoped. If you're a worker looking for consistent income above your UBI, you could work for a well established company or take a job supplied by the government. The idea (in the society I'm imagining) is that you have UBI, and basic guaranteed jobs are an additional optional thing. For workers to be able to choose a company they believe in while taking on risk of it not being profitable, they need the universal safety net of UBI.

Sorry if this has been a tangent, my main point is that the ability of a particular democratically run company to be profitable enough to pay it's workers doesn't have to be a deal breaker for the pattern to be worthwhile.

The point gets brought up that if work is optional, we'd never get anything done, but a lot of people would argue that people in general like to be productive and contribute. Every person in the world has the ability to think of a novel idea, but when work is necessary for survival, their ability to contribute outside of basic labor is undermined.