think AS cap should be 1.5. attack speed can be toxic. actually it is toxic. I will explain it
We have to champions. champion A has 2.0 attack speed and 100 AD
Champion B has 1.0 attack speed and 200 AD.
in simple evaulation. they both have the same dps? correct. thats simple . they both do 200 damage per second. However. here is when things get interesting. logically
Champion A will land more autos than champion B. which means. the autos that Champion B doesn't land is missed damage. nobody is ever sitting next to you leaving u free auto. at least most of the time. you always lose target. but
Champion A is more likely to land more than 1 auto in a trade. effects like lifesteal red buff benefit much more in that case. also. it becomes difficult to all in a champion that doesn't really have a window of weakness
a 2.0 attack speed 100AD champion has 0.5 seconds of no-dps. a 1.0 200AD champion has 1 entire second where they aren't doing trade damage lifestealing etc you name it.
there is a lot more outplay potential you have against low attack speed more ad target
HOWEVER on the other Side. that makes the game less snowbally and less punishing from behind. BECAUSE crit and AS and ad is so tired together. YOU NEED a lot of attack speed to be relevant as an adc (most of them). but if AD mattered more. that would be less needed stats to be effective. an AD with just an AD item would be more effective than an adc that needs to have attack speed and an ad item to dps.
obviously to change those things. the game has to change a lot and I think the ship has sailed on that.