Because my 15 minute drive can be a 60 minute drive depending on traffic and there are 3 viable routes I could take.

Traffic changes while I'm driving and it automatically updates. An accident can occur on a bridge I'm approaching and I can get detoured and save actual time that I can spend with loved ones instead.

If I'm driving later at night, construction may block off my normal route and I can still get wherever I'm going.

I also get notifications for hazards like objects on the road, disabled vehicles, or events that are going to cause traffic. (I use Waze)

And the cost is zero. When I get into my car it automatically syncs and off I go. There's no reason to NOT have it.