I'm not suggesting that everything in business benefits from being regimented but that meeting expectations allows for others to plan their time effectively.
Time where people are waiting for others to do work which should have been completed can often be wasted.
Then you must first consider the need to have the business or meeting in the first place.
In fact, people's time is only "wasted" because it has been made precious -- i.e. because it was stolen and/or sold. That's way more wasted time (they'll never get again) there, than in "wasting time" by not being punctual.
Societies studied by ethnologists had little care for punctuality. In fact the same was true for rural societies in Europe and the US as well (the US South was considered "lazy" and without a "sense of time" as well), and even urban life before the tyranny of the modern "always on" demands. For the upper classes, being fashionably late was a virtue.
Efficient towards what, and what for? Those are good questions seldom asked.