But it's
not a solution, that's the problem.
I am currently at my desk, in my office. Am I working?
For roughly two years during the pandemic, I was at home using my laptop. Was I working?
Furthermore, for most office work, there is more to working than a binary "are you doing it or not?" Being at your desk working says nothing about the quality of your work, which any competent manager should absolutely be capable of assessing from the work itself.
Finally, you're making a huge assumption:
> if there really is widespread slacking happening
Is there any evidence that this is happening? I guarantee you that the kind of manager who does this will not know, because they have no effective metrics.
It's also precisely the kind of thing that toxic management culture says workers are always doing (or trying to do): It perpetuates the idea that Managers, who are perfect, pure beings with only the Might Company's best interests at heart, are always at odds with Workers, who are lazy good-for-nothings only ever interested in getting the most money possible for the least amount of work possible, and who must always be treated as if they are trying to steal their time from the Mighty Company.