Why does Resetting settings speed up the phone?

[heythisisdave]

I've noticed my iPhone 6 Plus slowly getting slower (Outlook for iOs in particular takes 5-10 seconds to show on app load/switch). I've tried a bunch of things: Background App Refresh off for most apps, reduce motion - nothing really seemed to help.

I reset my settings this morning on my iPhone 6 Plus and it did seem to help - any idea why this is? What kind of settings slow down the phone?

 

[Shirasaki]

Guess the default works the best?

 

[beernut]

does reset settings require a reboot? because it's usually a reboot that will speed things up temporarily, not necessarily resetting of the settings itself (which is why most people suggest restarting/rebooting when an issue comes up)

 

[VSMacOne]

It just restores all the system and app settings back to default. Sometime they get bogged down over time due to various app updates, OS updates and bugs that appear.