However, some annoying apps will continuously notify you to open location service or something else as long as you start/use that app. Restriction could suppress such annoying on screen nags once and for all. One of such bad examples is QQ.
And, restriction could prevent new app from acquiring certain features.
Such restriction is also based on individual features, not "shutting down them all" approach. What it prevents in fact, is the ability to change it through settings app. When you click individual items, you can see you have the ability to "allow changes" or "don't allow changes", which is the core of restrictions.