What use for the mechanical key with smart key system?

I have a 2021 with smart key. When I purchased I got 2 FOBs and 1 mechanical key. (Edit: This post is specifically about that third and separate mechanical key, not the mechanical keys that are integrated into the FOB.)

For a long time I thought it was a valet key and then actually tested it today. It opens the glove box which seems like a dead giveaway that its not a valet key. It also does not start the truck, error message is along the lines of touch key to ignition button, which does nothing so I assume there's no chip of any kind inside of it.

I also double checked manual which didn't mention any valet key, but it did mention mechanical keys as an option for type C system (smart key).

So then: what exactly is the mechanical key good for if it unlocks but can't start.

 

When your battery dies and you need to unlock the truck to pop the hood. Just an easy scenario that it's good for.

It's specifically for the physical locks. Let your imagination run wild.

 

Alright, but in that situation my fob has the mechanical key as well, but point taken: it's basically a way to physically unlock the truck.

 

I leave mine in the truck so i can lock the tailgate if needed.

You can unlock your truck with the key inside the fob too.

 

I had a plain metal key cut at the local hardware store to allow me to leave my truck running while I run into a gas station, with my "smart key" still in the ignition, and I can lock the doors of the truck.

The truck wouldn't allow me to use a spare "smart key" (on my 2018 that means a key and fob combo unit) to lock the truck while it was running. But the $3 key I had cut at True Value does work for that purpose. Guessing yours could work similarly

 

Unlocking the tailgate with the FOB key can be challenging.

For that you can use the mechanical key which gives you more leverage.
Or FTW you can do what I did and install a power tailgate lock.

 

I put that key on a small ring with the keys to the tailgate/topper and trailer locks. It lives in my left pants pocket because it is frequently used. The fob lives in my right pocket along with a high speed lead dispenser, which is not accessed frequently.