My $350 Samsung A71 is two years old and feels brand new. My sister's SG9+ is 4 years old and the screen is broken in two different places, but is only asking

My $350 Samsung A71 is two years old and feels brand new. My sister's SG9+ is 4 years old and the screen is broken in two different places, but is only asking for a battery replacement. Iphones did provide security updates for longer, which is easier when you have few models and a huge userbase.