Earlier quoted context omitted.
I don't think it needs to be that grand of a scale to fulfill the reasoning. OP's example was a fellow taking time off and exercising his other interests in electronics by learning and experimenting. Another example might be a hobby. A hobby is a great example of a leisure activity as its [usually] done completely for its own sake. For instance, a sheet metal worker who spends much of their time off work playing in a…
To take the example at hand, for many young(ish) people taking time off work to learn electronics wouldn't necessary be a nice experience. Because their lives exist to a large extent in relation to work. They have moved to a new city, because of work. Where the live in a small apartment, to be close to work. They have friends, from work. And they have coffee on their way to work, to talk about work or even to do work…
My advice to the person in question would be to pull your head out of work and sample a little more of that big city while you're paying so much to be there.
There's no reason why every moment of time that isn't paid for by work to be spent on work, outside of that being a choice (given our current example, which sounds like a well-enough-to-do tech worker).
Personally, I couldn't live that way, and I'm probably filling out a few of your checkboxes above. I like the people I work with, but I value [and fear] time too much to give it all into my job—be it tasks, networking, socializing, whatever.
The example you extended sounds more like a problem of agency than one of [a lack of] leisure.