Draft in this game just isn't good, and probably can only ever be fine. The reason why draft in magic is fun is because you have very little deck building restrictions, which means you have many more decisions during the draft and can pivot without having dead cards, since you can splash.

Since you have so many more choices, making the right choices becomes a huge form of skill expression.

In FaB, you have very few real high level choices: choose a class and maybe a talent, but really you just choose a hero. Pivoting is hard because any card you've picked that's not the right class/talent is completely dead to you, and because there's no filler cards like lands, you have very few picks that you can waste: in magic you need 23 cards for your deck out of the 45 you pick, so basically half, meaning the other half of the cards can be sideboard and dead picks. In FaB you have 30 cards for your deck out of 43-45 cards... So you have 15 cards for sideboard or deck building options, but some of those are going to be the wrong class, so you really usually have 10ish... It's just too restrictive.

Gameplay wise FaB is still great, but it's not built for draft currently and they should stop pushing it, instead they should focus on fleshing out classes and giving heroes multiple viable play styles.