Delete unused apps and set your phone to flight mode when not using it. This does wonders to your battery life. A 5 year old phone can last a week.

Of course this doesn't work if you're expecting to receive calls or notifications.

What’s the point of having a phone then ?

I personally buy mid range phones for around 400$ and then buy new after 2 years.

Better than buying a 1200$ phone and expecting it to last 5 years