Does an invisible familiar delivering a touch spell have advantage?

Question

Since a warlock's familiar can be a Quasit (which can turn invisible) and a familiar can be used to deliver the warlock's touch spell, it should be able to deliver a touch spell like plane shift¹ (when used on unwilling creatures) while invisible.

But does the familiar get advantage on the attack? The wording of the Unseen Attackers section is quite specific about saying “you”, which I interpret as the caster, not the familiar:

When a creature can’t see you, you have advantage on attack rolls against it.

Does the Advantage apply or not?

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1) Plane Shift is horrible as an offensive spell. However, this question might be relevant for Multiclassed warlocks.

Answer 1

Yes, advantage applies

Why? The you in the unseen attackers sections is referring to whatever creature is invisible / can't be seen. In this case it is your familiar, and it would have advantage even though it uses your attack modifier.