Jinx is a champion that has large lost meta relevancy. We all know she is fundamentally flawed in that you need to ditch your whole hand to get her pay-off, but then she can't be protected with an empty hand.
Jinx might benefit from a pick a card style card in PnZ, where you draw cards the next turn, so you could level her and then immediately refill. But we will never be able to print such cards with TF around. TF is most of the reason why each region is not allowed more than 1 generic draw card, to avoid a critical mass of draw.
Riot might want to print another flavour of an existing card. Maybe 6 mana draw 3. Or a decimate that did 6 but healed 3 right after. A slightly different spin on an existing idea. For general/toolbox decks they will be content with picking one flavour or the other that suits their need better. But there will exist synergistic decks that will choose to play both flavours, because the idea is so in-theme with the deck that they can never play too much of it. And that may allow them to hit a critical mass to become degenerate.
That is the idea of design space. Three (or 4 or 5: remember, without rotations, the library will only keep growing) cards that do similar things can coexist if they don't appear in the same deck and each deck picks their preferred flavour. They become problematic when they get ran in the same deck allowing a highly synergistic deck to run 9 copies of their best card. So the only option is to rotate out the old version and replace it to put a fresh spin on the game (think in 10 years time: trading card games can easily last that long).
Edit: To people mentioning that BW has enough good draw, eye is a relatively recent card and TF has in fact become much strong since its printing. Also, TF doesn't love draw as much as under-costed draw with downside, as leveling TF is so powerful that almost any downside is worth it. Rummage + stress testing, glimpse etc. Thankfully none of these draw has been printed that regions that can also protect TF well. IO arguably has cheap draw and also protection, and IO TF has been quite good, but even IO does not hit the critical mass of cheap draw to make leveling TF consistent.
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