When people are left to their own volition, you get to see their character. It's what people do when no one is looking or supervising that is important.
I see people who look busy, but it is obvious to me (an outsider looking in) that they are just looking busy for the sake of looking like they are doing something. When you don't want to be at work, it is more obvious than some may think.
What a boring, slow-moving day this makes. What an ineffective employee this makes. What an ineffective business this makes.
The answer is motivation. Yet this is not an easy thing. The real, effective motivation must come from within the employee. The management can only spark the motivation by helping the employee realize their own motives and make better use of them. The best way for both is to tie the work to the employee's highest values and that probably is not money, but something else more powerful. Find what those things are and the business and employees will thrive.