Companies should be judging their people by results. If someone's performance is acceptable then all of these surveillance metrics don't matter. If someone's performance is not acceptable then all of these surveillance metrics still don't matter. If the company can't tell if an employee's performance is acceptable then maybe that's something they should think about first.
Some of the nastier management practices are also CYA policies because of potential liability if the employee does something they shouldn't or suffers some harm personally while working from home and the company is held responsible even if there was little it could or should practically do to avoid the harm. It seems likely that some of our legal frameworks for employment relationships are outdated in the WFH era and could benefit from review. It should be clear what responsibilities an employer has to a WFH employee - for example providing WFH staff with suitable equipment to do their job properly and safely - but I don't think we should burden employers with responsibility for bad things that happen beyond their reasonable control. Maybe some of the perceived need for these aggressive and often covert surveillance measures goes away if some of the arguably unreasonable liabilities for bad things happening are also taken away.