Use your phone for 25 years. iFixit on right to repairs remaining obstacles, hope

“I think we should be talking about lifespans of smartphones in terms of 20, 25 years,” Wiens said.

Source: The same phone for 25 years? iFixit on right to repairs remaining obstacles, hope - Ars Technica

Keep in mind, your old phone might be better as a security camera, sound machine, smart display, or video game console.