Instead you could spend $10-20, be able to buy a couple in case you wanted some backups in certain situations and not have most people replace their phone when their batteries start losing juice and make their system feel sluggish.
All to have a slight thinner device.
Yeah, I miss the old Nokia battery system and ironically technology has made it all more painful since it is now once or twice per day instead of per ~week that you might realize you want to go out but have put off charging.