Rare items are a step-up from Magic items providing one additional modifier.
Rare items are useful while on the hunt for Legendary or higher items. Do not dismiss them though, they can be used to turn into a Legendary items though the Legendary Aspects crafting system at the Occultist.
Some stats on Rare items may suit your build better than a Legendary and therefore they should not be dismissed and stats should be compated closely against other Rare and Legendary items in your inventory.
They are also useful when broken down crafting materials at the Blacksmith
Diablo 4 Item Tiers
The tiers of items progress as follows.
- Normal: 1 modifier
- Magic: 1 random modifier
- Rare: 2 extra random modifiers
- Unique: Fixed affixes, class-specific
- Legendary: 2 random modifiers and 1 Legendary modifier.
- Set Item: Unknown
- Ancient Set: Unknown