My Case for why Guinsoo's Rageblade needs to be removed rather than nerfed
Fundamentally, Guinsoo's is a "cool" item and fun in theory. It is hybrid, easy to build, and encourages a long trade playstyle. Cool, that is unique.
In it's current state it gives a butt ton of stats for very little gold. Attack Speed, AP, and AD that scales to really high amounts for being in long trades.
Guinsoo's has always done this, but before it was NEVER used. Now that its buffed, it is being picked up by just about anyone who can abuse it even slightly.
This item I feel is not going to be able to be balanced. You can't. if you give it great stats for scaling in long trades, then it will be bought by everyone. If the stats just aren't worth it, it will never be bough except maybe by niche users occasionally. (Jax/Kayle could buy it before, it just wasn't the best item)
I feel Guinsoo's just needs to be removed altogether. I'm not entirely sure as to what would replace it, but I'm sure Riot can figure out another new hybrid item that suits the champs who were going to use rageblade.
Maybe an item that amplifies another aspect of a champion when they auto attack X amount of times. It can give raw AP/AD. and then after being in battle for X amount of attacks or time it can then go into its passive that maybe increases ability damage slightly?
maybe not the best example or idea, but rage blade is just a state mounting beast that will never be able to be balanced in my opinion. It just means the longer you are in battle the stronger you are going to be and if your opponent didn't buy the item, your item is going to be more efficient unless they can blow you up VERY fast.
it is overall an unhealthy design.