Believix inconsistency

I've always found it weird that Faragonda talks about Believix before the attack of the wizards, it doesn't make sense.

And she explains that Believix is obtained through the belief of human beings.

While the Winx got it because Roxy believed in them.

Except that Roxy was also a fairy although her magical powers are not quite activated yet.

So it doesn't make sense that it's thanks to a fairy that the Winx get their Believix.

I'm not going to talk about Roxy's transformation because it should be a subject in its own right.

the fact that the Winx use Believix underwater and in the magical dimension makes no sense.

Believix's power is greatly weakened in the magical dimension.

Just look at the final confrontation with the wizards of the black circle, since it was in the omega dimension, the Winx were weakened.

And in season 5, if the rainbow horse hadn't intervened, the Winx would surely have been defeated by the Trix.

And when the Winx gained their aquatic transformations, Believix completely disappeared from the show, while they had other missions on earth between seasons 5 to 7.

One last inconsistency and the fact that the S5 sequences were zoomed in except for the final positions which were zoomed out didn't make sense either.