That's a lie.
I've practice a lot of Katarina post rework and what you are saying is absolute lies.
Yes, she doesn't have to wait for her "burst" if her burst is just
EQ gunblade and R.
Which will translate into:
15 / 30 / 45 / 60 / 75 (+ 50% AD) (+ 25% AP)
+
75 / 105 / 135 / 165 / 195 (+ 30% AP)
+
25 / 37.5 / 50 (+ 22% bonus AD) (+ 19% AP) per dagger with each dagger getting shot every 0.166 seconds
for full channel: 375 / 562.5 / 750 (+ 330% bonus AD) (+ 285% AP)
for 1 second if we are talking about insta burst it would be 6 daggers.
Or: 300 + 132% bonus ad + 114% ap
And finally gunblade
UNIQUE – LIGHTNING BOLT: Instantly deals 175 - 253 (based on level) (+ 30% AP) magic damage
So, assuming max level for all abilities and lv 18.
We have:
75 + 195 + 322 + 253 as base damage 845 damage.
+50% ad + 25% ap +30% ap + 132% bonus AD + 114% ap.
For a total of +50% ad, +132 bonus AD + 169% ap.
Kat has 112.4 AD at lv 18.
Gunblade has 40 AD
So, that means kat has 152 AD, with 40 being bonus ad.
So, she gets 76 damage from 50% ad.
And 52.8 (lets say 53) from the bonus AD scaling on her ult.
So, that's 129 damage +169% ap.
Generally a full kat build has around 500ap or so.
80ap
80 ap
70 ap
80 ap
120 ap (+35% ap)
580 with above build.
So, the 169% ap would mean: 980 damage.
Which is 1109 damage from scaling.
And 845 base damage.
For a total of: 1954 damage.
Which is very low for a lv 18 burst.
For you to understand just how low that burst is. This is Syndra's R.
1260 (+ 140% ap) at max lv and max balls set-up.
So, if we say Syndra also has the same build with 580 AP.
Syndra would do 1260 + 812 damage, or 2072 damage.
While a feed syndra just like a feed katarina can one shot you fairy easily. Assuming a non feed situation, that damage is not enough to kill the enemy adc or mid laner. You won't be doing true damage to them. And they will have heals and shields and peal from their team.
Anything below 2500 burst will not one shot unless feed while you are underfeed or without any resistance items or support from your team.
So, in order for Kata to exist in fights and so on, she has delays, more exactly, on her daggers.
Her usual combo would be: E gunblade Q W, pick W and hit the target with passive, then E on the target to also pick up another passive from the Q and then R. Or E gunblade Q W R and your combo is complete when then W is picked up.
This is the scaling on Kata's daggers:
dealing 75 - 287 (based on level) (+ 100% bonus AD) (+ 55 / 70 / 85 / 100% AP)
So, that's 287 base, with +40 from bonus ad and + 580 from the ap. For a total of: 907 extra damage by picking up a single dagger (usually W) or one that was set-up before hand.
And adding the 907 to the damage above, 1954+907 = 2861 damage, which is above the 2500 mark which gives her a chance to kill her target.
But again, you got a delay till the dagger from W falls to the ground (1 second, well, 1.25s) where the target can escape.
And ofc, if we add in another passive proc and another E proc, then the damage will go above 3500.
So, she either has a delay in her assassination or the target must be stupid enough to walk over daggers planted and visible on the ground (unless is a brush).
Saying that Kata has no delay is absurd.......... Yes, a feed Katarina can one shot easily.
A fed Zed is going to kill you with just his WEQ, maybe a W swap and hitting an auto attack at most.
A fed Draven is just going to auto attack you twice and you are dead and that takes less than a second as well.
A fed vayne can just Q aa aa and you ded.
But we are not judging balance by fed champions.....