Today I was working on some POC on a trail instance and observed that there is something called “Toast Notification Display Time” option under Settings on the Ribbon.
Let’s try to understand what are Toast Notifications. For example, if you have created a record using Quick Create, you will see a message after creating saying “Your changes were saved” as shown below.
These are Toast Notifications and these will shown on the screen for some seconds and disappears.
This particular setting Toast Notification Display Time will extend the notification display timeout to 10 times and it is default.
A quick search on this, make me understand this was added for Accessibility reasons.
Hope this helps.