My iPhone 6s is still working fine after 7th year birthday. It had under warranty battery + screen replacement at the end of 2nd Year, followed by a battery swap at 4th year. Around 2% pixels are dead, but the phone still works as expected. It has 4G, so data speed is also not an issue. No lag whatsoever. All my apps continue to work. I have come across only ONE generative-image app, which failed to install claiming need iOS 16+.

Now I am actively waiting for this hardware to FAIL so I can justify myself buying a latest model. :)