Basically, there's no noise isolation at all, even less than with standard earbuds. You push the volume up to compensate for noise and damage your ears. Take away: use them at home or in quiet places, don't use them in the street, subway, or other loud environments.
British journalist Carole Cadwalladr gave an impassioned speech at the TED conference where she took on the silicon valley big guys for their role in the brexit mess. Predictably, their reactions weren't very warm.
"The current service economy makes the middle class the working class and the working class the working poor. […] So, the next time you use an app that makes your life simpler and more convenient, spare a moment to wonder whether it’s making someone else’s life much more miserable."