There are many problems with that. For one there are security issues. There was an article just recently on HN that reported a large attack, exploiting the invasive nature of these tools. Secondly they are useless. Third, they are inhumane and show that there is a severe lack of human connection trust in these work environments.

Also, it is not strictly "their" device in every case. There are firms that require freelancers/contractors to do the same on their device.

This kind of behavior is a huge red flag, but too many juniors otherwise naive or desperate workers tolerate it.