Apple should just make another new iPhone in the 5s body. They did it before. Do it again.
@zak I can understand that. My 5s is on iOS 12, so I only use it to have an additional phone plus very dedicated purpose - never use other apps or data, and a separate dedicated Apple ID. My iPhone SE is on iOS 15, so it still gets daily updates of many apps. But I may be an odd one; I use a desktop/laptop for most of my tasks. I think it had been different if I had used my phone more extensively.
@hehemrin I just don't think I'd feel comfortable using a phone that's no longer running the latest version of iOS, even with security updates available.