The key point from this article to me is "just telling someone I was going to do something made me get it done".
So what keeps me on track is that I discuss with the client every week or few days what it tasks I should to try to complete. This is based on his priorities for requirements and the technical issues that I know about. Usually there are one or two primary tasks and one or two secondary that I honestly say may not get completed.
Every 1-3 weeks usually one or more of these items is something concrete that is supposed to show up in a computer program or report that the client will actually see or touch.
So for there is usually already an accountability structure. It's just not someone looking over my shoulder constantly.
I have actually worked on Upwork or whatever they call it with the constant screenshot of what you are doing. To be honest, in a way that does make you productive. However it also makes life more stressful. And I feel like I would prioritize more poorly because I didn't want to look idle so rather than doing a hard task that might require more thinking or googling or something, I might be more inclined to tackle easier tasks that would make things seem more productive from the screenshots. Overall there was just a constant distraction of wondering what people would think if they reviewed the session. I would never willingly choose to work like that again.
When I don't actually have someone looking over my shoulder I honestly do spend somewhat more time on non-work items. However, it seems like my this is automatically limited by the needs of the task items which I will be reporting on to my client in a few days or a week. And even on days when I am getting distracted, I put my main energy into my tasks until they are completed.
The idea of absolutely constant supervision during work only really makes sense when there is no trust or real respect for the worker and no other way to have accountability. I am worried that this type of article or service may reinforce management's tendencies to not respect or trust workers and want constant proof of total productivity from the wage slaves.