(disclaimer- long post b/c I’m very passionate about this subject, there’s a tldr at the bottom :)
As the creator of this thread mentions theorycrafting itemization, which is a big one, and it would also allow you to diversify your build mid-game to counter your opponent’s defensive stats (i.e. he stacks armor, you go from pure ad to hybrid).
From a game-theoretic point of view, making the hybrid path feasible is interesting because it increases the branching factor of the game (number of possibilities at each node of the game tree) for each player.
The reason I switched to lol after playing dota for years was because I knew that lol was more interesting because the items actually interacted with the hero’s abilities. Coming from dota this was a novel concept and very profound in the implications that it has for the subsequent possible strategies available to players.
For example, in dota one can buy items that interact with their champ's base stats to increase things like attack damage, attack speed, mana ... but no item can increase how hard your 'Q' hits or buff the damage on your ulti.
For me, a connoisseur of strategy, this is essentially the difference between going to color from monochrome. In dota, each champ is born with a major stat (Int, Str, or Dex), and you must play to your major stat. Lol, seemed much more fluid at the time. It was cool to see that you could build Twisted Fate AD and wreck house, or sit back, stack AP and throw cards. You could build hybrid pentakill jax, or ap assassin jax...etc. As a longtime magic player, I saw each champ as a deck archetype and the items as cards to change out. Therefore, the more possible viable cards, the more interesting the format. Sorry for the analogy, my reasoning was basically ‘there were many more possibilities in the new game, so it is deeper and more interesting’.
And since then, it seems like even though there are champs who have technically have duel ratios, for the majority of champs, one ratio is usually hands-down superior over the other, it feels more dota-esq, like you’re born with a major stat that’s the only good way to play the champ.
TLDR; Making the hybrid path feasible is interesting because it increases the theorycrafting and number of possible strategies that a player or team can bring to the game.