It wouldn't make sense for the operating system alone to consume 2GB RAM/16GB storage, but an Android version number also represents a compatibility level for apps and handsets.

If an app developer tests their app on Android 13 but doesn't test it on older Android versions, they probably aren't testing on low-RAM devices, either. And if a consumer buys a handset after checking only the Android version number, and doesn't check details like the RAM and storage, they'll probably be find out that apps which they expected to work don't work, and be quite unhappy.