Within the Intune MDM space, a separate partition is created on the device that essentially isolates work apps/data from personal apps/data. I, as a sys admin, have control over the "work" space, but no control over the personal side of things.

We don't have a very heavy handed approach to monitoring usage etc for mobile devices or even laptops and this has been the case with most of my previous jobs.

That said, I'm sure there are IT departments out there with a ton of staff and a big budget that can and will get quite granular with what you are doing on your devices (keylogging, etc)