How long will my phone last?

I currently have a iPhone 6s Plus. I financed it with Verizon in August but I just paid the whole thing off to lower my bill. It serves me well and I don't need a new phone even though I always want one (same way about cars lol). My previous iPhone 5 lasted me 3 years I was wondering if you think I can get the same time out of mine? The battery in iPhones die fast when they are older.

It will last for the amount of time that it will last for, because that is the amount of time that it will last.

The better you take care of the phone, the longer it should last. Doing what you can't to drop the phone onto hard surfaces, keeping moisture out of the phone, steams sweaty pockets, high humidity, and submerging, will go a long way to keeping it working.

Batteries can be replaced, so don't worry about the battery getting older.

I have phones that are well over ten years old that work perfectly fine.