Sure, Daria was first introduced in Beavis and Butt-Head (1993). Sure, in that series, she was only a supporting character. But, this is totally independent of B&B.
For one thing, B&B focused more on the moronic exploits of two moronic characters (Don't get me wrong, I love B&B. But in a totally different level.) while Daria focuses on someone whose brain actually functions.
For another, this series can easily stand on its own, with practically nil reference to its "origin" series.
A third reason is that the characters are not as predictable as they are if we are to compare them to other similar series (that is, if we can take any other series to have a similar premise).
Fourth, most of the characters are not as one-dimensional as could be expected of a cartoon. I mean, even the characters generally portrayed as dim-witted actually provide have some sensible insights every now and then.
Fifth, you have to enjoy the not-so-subtle socio-econo-political commentaries that abound the episodes.
I'm one happy viewer that the creators/writers decided to have Daria move from Highland to Lawndale, and to eradicate (or at least minimize) any connection to the B&B series. Daria can easily hold her own, as a character, and as a series.
That unfilled star in my ratings? Just a jack-ass comment that Daria's own series should have at least used different animation styles for the backgrounds. Otherwise, this is a 10/10.
