The problem with that is that the best jobs (such as google) are competitive. Even if two people competing for the same job only want to work 30 hours per week, they both know that they can make themselves more attractive to the employer by offering to work more hours than the other person. This is especially true for immigrant groups competing with domestic labour.
The state could regulate the working week to 30 hours, but this will impact GDP and thus the state's ability to provide public services via taxation and also the ability of poor people to get out of poverty by outworking the more wealthy.
The state could regulate the working week to 30 hours, but this will impact GDP and thus the state's ability to provide public services via taxation and also the ability of poor people to get out of poverty by outworking the more wealthy.