Maybe the key insight here is the pivot from prohibition to differential friction. By architecturing high activation energy for distractions (black UI, location blocks) while maintaining low friction for utilities, you've essentially created a "price spread" between productive and unproductive uses of the same capability.
I suspect we're seeing an inevitable arms race: platforms driving activation energy toward zero (think TikTok's frictionless feed) versus commitment devices manufacturing artificial friction. Perhaps the sustainable equilibrium isn't digital abstinence but rather carefully engineered friction differentials that respect our inescapable need for connectivity.
You need to make ONE OF THEM more inconvenient to use, so that overall your bathroom experience remains useful and convenient. (You'll see this often with a sliding door between two installed rolls of paper, usually with a visible window showing the amount remaining)
Introducing "artificial" inconvenience can be a very powerful usability improvement.