Can't speak for all companies, but I know most, if not all, companies in my industry make you essentially sign over the rights to your phone if you want to be able to access your work email or anything accessible through the work VPN. Before being able to access any of this they'll put company security measures in place (which in every case so far has included some form of security software capable of tracking screentime, inputs, downloads, uploads etc.
The nice thing about this is that (in Canada at least) they can't force you to sign it it all over, and not signing it is all wins in my perspective.