I think that the Infinity Edge rework was a failure. Whatever, keep it as it is. The change that would be healthy for adcs is a crit item that is cheaper and weaker than the ones we currently have. Crit is expensive and 2 zeal items with Infinity Edge overcaps the crit bar.
A 15% crit item would give you 80 crit and a 20% crit item would give you 100 crit. So either one new item with 15% crit and attack speed (or damage or defensive stats, but I think that attack speed here would be good) or two new crit items with 15% and 20% crit and some other stats where attack speed would be prefered or some defensive stats like armor or mr instead of damage would be very healthy for the role.
If this gets implemented tho I do require being credited Kappa
Edit: The comments are trying to advocate inefficiency - stop doing that. Adcs dont have as much variety as for example champions who benefit from cooldowns.
Heres an example, go into a game, go into items and check your options under "crit". Not a big selection. Now you do the same on for example "cooldown reduction". Adcs dont have a lot of options.
I think that the balance team failed when they instead of making adcs have more variety they give the role more variety.