If you don't have root, you are not the device owner, you are a lessor to whatever companies and carriers are subsidizing your out of pocket costs. This includes iPhone and it's walled garden approach (delete Siri - you cannot, GBs of space is permanently wasted on most users and it still drains the battery when fully disabled). Locked, unlocked, and root are terms the general public has no clue about.

Whenever someone buys an unrootable phone, ask them if they enjoy living under HOAs. That's the same level of control they've agreed to without root. Framing it this way will neatly land your point and just maybe reset their concept of what they should have purchased.