Item level has never been a stat to base the "this pointy stick is better than that pointy stick" by, stats on each weapon vary and BiS is not so simple as just getting the weapon with the highest ilvl, although it's a good basis if you're not interested in trying to learn the stats. Really all Ilvl does is, as you said "the answer is the same", it applies a way for the game to restrict/filter matchmaking as we discussed.