Just because there are bigger problems, it doesn't mean there isn't demand to solve smaller ones.
For example, most of the churches where I live have a big meeting room underneath their main worship space. This room has curtains to divide it into smaller spaces for a dozen or more different meetings, including Sunday school, where a dozen (often noisy) children might be in each room.
Having curtains that genuinely reduce the noise between the areas would make a huge difference! It would reduce the demand to build new buildings with separate walled rooms that wouldn't be used most of the time.
Adding flexibility of use to larger spaces with a variety of demands is a problem worth solving, even if it's not as big of a problem as motor vehicle noise in large cities.
For example, most of the churches where I live have a big meeting room underneath their main worship space. This room has curtains to divide it into smaller spaces for a dozen or more different meetings, including Sunday school, where a dozen (often noisy) children might be in each room.
Having curtains that genuinely reduce the noise between the areas would make a huge difference! It would reduce the demand to build new buildings with separate walled rooms that wouldn't be used most of the time.
Adding flexibility of use to larger spaces with a variety of demands is a problem worth solving, even if it's not as big of a problem as motor vehicle noise in large cities.