Faerie Fire: Uses, and effects

For reference: 

Faerie Fire Spell:

Due to the wording of "Affected creature or object have advatage," does that mean, since the creature makes a saving throw, which affects them regardless of what they roll. Does a creature that attacks a different affected creature have advantage even if the affected creature still succeeded on the saving throw?

Note: I know that some people are going to say that this is a non-good faith interpretation, I know it's not, and I wouldn't rule it like this, I simply want to know people's opinion on this topic

If you know you are wrong, why are you asking the question?

I'm not neccessarily saying I'm wrong, I'm saying it's already been overrided

Quote from Tana___ >>

For reference: 

Faerie Fire Spell:

Objects in a 20-foot Cube within range are outlined in blue, green, or violet light (your choice). Each creature in the Cube is also outlined if it fails a Dexterity saving throw. For the duration, objects and affected creatures shed Dim Light in a 10-foot radius and can’t benefit from the Invisible condition.

Attack rolls against an affected creature or object have Advantage if the attacker can see it.

Due to the wording of "Affected creature or object have advatage," does that mean, since the creature makes a saving throw, which affects them regardless of what they roll. Does a creature that attacks a different affected creature have advantage even if the affected creature still succeeded on the saving throw?

The creature isn't affected by the spell if it succeeds on the saving throw, so attack rolls against it don't have advantage.

Just having to roll a save doesn't count as being "affected" in this context. If it did, there would be a lot of spells and other effects that would either not work at all or work very differently to how everyone understands that they work.

Why doesn't a save count as affected?

The first sentence of the spell description details the effects on objects within the area. 

The 2nd sentence  says that creatures in the area are also affected IF they fail a saving throw. Meaning that a creature that succeeds its saving throw, then it is not affected.

that is how English works (and I say this respectfully).

Quote from Thyrwyn >>

The first sentence of the spell description details the effects on objects within the area. 

The 2nd sentence  says that creatures in the area are also affected IF they fail a saving throw. Meaning that a creature that succeeds its saving throw, then it is not affected.

that is how English works (and I say this respectfully).

 I'm talking solely about the last sentence, as it is the one that gives the advantage.

Creatures that succeed in their saving throw are not affected by the spell, therefore attacks against them do not have advantage.

Quote from Tana___ >>

Why doesn't a save count as affected?

If it did, that would mean that success or failure on the saving throw has no mechanical impact at all, since all the effects of the spell that actually have a mechanical impact are only applied to "affected creatures" or "objects and affected creatures".

Does it make any sense that a spell would be written to require a saving throw, but for the effects of the spell to be exactly the same whether you succeed or fail?