They always rely on kernel extensions, undocumented functionality and hiding a lot of stuff in your hard drive, in locations that are often in your (and Apple's) interest to protect, or even to routinely clean.
I also remember some scandal a couple decades ago with some plugin scanning your /etc/hosts file for their domains. I'm pretty sure there's more egregious stuff going on.
I swore off iLok about a decade ago when I had to go into a studio and couldn't get the goddamn thing to authorise anything and had to spend a few hours in support. On my local machine I could just buy stuff then immediately pirate it for stability, but on a studio that was not possible.
I'm ok with other people using, but I'm tired of those software makers treating my computer as if it was their playground.