I have not experienced this at all. Last year around this time I upgraded from an iPhone 7 to a 12 simply to get better camera lenses for a trip rather than buy

I have not experienced this at all. Last year around this time I upgraded from an iPhone 7 to a 12 simply to get better camera lenses for a trip rather than buying a new camera and lugging that around. The 7 is still sitting on my desk and works fine, was going to get trade in credit somewhere or donate it. Also going to throw this out there (and I'm preparing for the commentary "you're saying don't use it herr derr") - are you on it a lot? I've observed my teens usage patterns and sometimes they are habitually just pulling the phone out and looking at the lock screen. This happens multiple times in minutes and the on/off of the screen is going to burn battery faster with no real usage. You may also have apps running in the background that use wifi/cellular, and that will drain the battery faster too. If you changed those settings to only use the network when the app is open then it will use less battery. Yeah you won't get updates when you aren't looking at those apps but, is that such a crucial thing? You can take the phone somewhere and have them replace the battery for far much less than the cost of a new phone.