It’s actually not that hard. If the assigned tasks are being fulfilled within set parameters there’s really nothing to observe and keep track of. What they’re worried about and what they can’t monitor and observe is what the employees are doing outside of those tasks.
My friend works from home he does all his work and in the down time he’ll run errands, work out, and play pool at his local bar. Whatever. His work is fully completed and submitted and his performance views are top notch.
And that’s pretty much the only thing employers need to be worried about. How well the work is being completed.