Upgrading to an iPhone 16 seems like a weird choice, given that the SE3 exists and it pretty much perfect. One argument that I can see it that the 16 is two years newer, and should get updates at least two year more. The price difference between the two phones however is much to big to justify getting the 16, unless there's some feature you really need.
Hey, author here. I decided on the 16 since its support lifetime started this year. If I'd gotten the SE (which I seriously considered since it has a more appealing form factor and touchID) I would only have a 4 year support lifetime as opposed to the full 6.
On the other hand the SE3 is 54% of the price of the 16 (assuming base models of both), so long term it could be cheaper to go with the SE3 even though you would have replace it sooner.
