"She is not more important than you."

Translation: Dia tidak lebih penting daripada kamu.

[JamesTWils]

Why must this be "daripada" instead of "dari"?

[Rick392366]

Why must this be "daripada" instead of "dari"?

"dari" = "from" (indicating location).
"daripada" = "than" (used for comparison).

Tini lebih cantik daripada Sri. (Tini is prettier than Sri).
Tini lebih gemuk daripada Sri. (Tini is fatter than Sri).
Tini lebih tinggi daripada Sri. (Tini is taller than Sri).

[JamesTWils]

Thank you. I clearly thought we had used dari for than in this lesson.

[Rick392366]

Yes, that's true.
"dari" can also be used for "than" (as a comparison), especially in colloquial/informal form (see below).

https://kbbi.web.id/dari

dari/da·ri/ p
8 cak
kata untuk menyatakan perbandingan: harganya lebih mahal -- emas;

The official KBBI definition mentions this as "cak", meaning "not official", "colloquial".

So, it's not wrong or incorrect to use "dari" , it's used frequently in the colloquial/everyday speech.
In formal speech, it's better to use "daripada".

https://kbbi.web.id/daripada

daripada/da·ri·pa·da/ p
kata depan untuk menandai perbandingan:
buku ini lebih bagus -- buku itu

It's the same definition (the same as the 8th definition for "dari").

"perbandingan" = comparison.

[Rick392366]

Thank you. I clearly thought we had used dari for than in this lesson.

Yes, you're right, the following sentence uses "dari" (for comparison) :

https://forum.duolingo.com/comment/28902715

That's the reason I've reported that sentence.
Not because I'm trying to be strictly formal, but because I think it's not correct to reject "daripada" in favour of "dari".

[kylaye]

Why is it "tidak" and not "bukan"?