I'm on my fourth smartphone, a first gen Motorola Moto G, which I've had for nearly 2 years now. The previous three smartphones I switched after about 18 months with each, at that time phones were improving fairly rapidly and each new phone was a good upgrade in one or more ways. All bought used, looked after and sold off again. I think they cost £150, £90, £80, £70 or so and sold for £50, £25, £50. As others have commented, smartphones are maturing as happened in the PC industry, so I don't see the need to upgrade my current phone at the moment. I don't use it for games and the battery is still good so there is no compelling reason to upgrade really. I wouldn't mind a better camera, higher resolution screen etc. but the difference doesn't seem worth it. The only issue really is software security updates, as my phone hasn't had a new software update available for a few months now, I suspect it will get at the most one more. On the one hand I don't install unknown apps / click on any old link etc. so maybe don't need all the patches, but on the other hand I would rather have security patches applied as some issues can occur without me doing anything silly. So I suspect I'll upgrade it in about a year for a newer Moto G or similar ~£80 budget Android phone just to get a phone receiving patches.