So what is the reason for Buff timers showing??

Bookkeeping is annoying and not-fun but it ends up being something you would have to do otherwise. Building the timers into the system lets you focus on playing the game instead of setting egg timers and comparing timestamps.

Clarity

Clarity regarding dynamic Q. One of the advantage you have when playing with a group is that you are more likely to be aware of the jungle timers. They probaly just want to make sure the Solo Q players doesn't have this as a disadvantage.