iOS updates and Android updates work differently. First and foremost, the biggest features in Android in recent memory have not even come from system updates. Nearby Share, Google’s version of Airdrop, and RCS, Google’s version of iMessage, are arguably some of the most important releases the company has made in a long time when it comes to really improving the experience of owning an Android phone for the masses. Neither feature required a system update. Nearby Share was delivered to every Android phone running Android 6.0 and higher through a simple, essentially invisible update to Google Play Services. RCS was delivered in a similar manner, through an app either pre-installed on the phone or easily obtainable via the Play Store. Most of the components are modularized and updated as such after Google rearchitected Android through Project Treble.
That’s in stark contrast to how Apple handles iOS. On an iPhone, even minor features are often dependent on a full system update. It’s for that reason that an old, unsupported Android phone is usually much more useful than an old, unsupported iPhone, even if that iPhone got more updates during its lifespan.
The main issue is whether an Android phone gets security fix updates on time or not.