A lot of the issues with modern electronics are down to the requirement to use lead-free solder for environmental reasons.
But ultimately much of how electronics are seen is down to the rate of progress with the electronics - a device made five years later than another will be so much more advanced that few people will want the five-year-old one, which makes it largely worthless even if it was working perfectly. So why bother making it last twenty years? Not to mention the fact that the limiting factor is usually the lithium-ion battery - you could have a mobile with a Ni-Cad battery, but it’d be hopeless. Keep changing the battery and an iPhone will quite happily last well into obsolescence. Or if you just want literally a mobile phone, buy one - no one is stopping you!