All that Apex's aim-assist really does, is lower the rotation speed when an enemy is near your crosshair.
What does this mean:
- When an enemy is near your crosshair the same input means less rotation.
- The additional acceleration to your rotation is completely removed.
- The aim assist is enabled when any enemy is near your crosshair, but not necessarily in your crosshair. This means that firing your gun while the aim-assist is active does not guarantee you hitting that person.
- Aim assist does not directly move your camera*
- Stick drift, in combination with strafing means, that the aim assist will slow down your stick drift at the edge of the enemy.
- Expert players can use this to then aim at their enemies.
Furthermore aim-assist doesn't always work:
- It doesn't work if the opponent is too close or too far away (from my experience, within ~3 m and outside 15-25m)
- There are numerous bugs with the aim assist including:
- Doesn't work if the opponent is looking at you
- Doesn't work if you have lag
- Doesn't work if the opponent has lag
- Doesn't seem to work if Jupiter is in retrograde*
- This is only partially a joke, because Respawn seems to break it about once a year for multiple months
Finally rotational aim assist has a specific deadly issue: It works by slowing down your aim. That means that if an opponent is moving close to you, they can and will outrun your aim.
We haven't even taken into account the fact that recoil removal "techniques" (read bugs that Respawn won't fix) can just straight up remove the recoil from guns (things like jitter aiming, recoil smoothing, and more).
Specifically recoil smoothing (strafing + counter aiming) aligns perfectly with how rotational aim assist works (you want to keep your crosshairs moving for it to actually do anything). This is why most controller players use it, since it helps your aim (as intended) and removes all recoil (due to the "exploit"). Which is why good players can use that to beam you.
M&K can do that too, and from a lot further away, but this is the technique that a lot of controller players use.
Professional players, like Hal, also have another relevant factor to consider: Comfort. It is not uncommon for M&K players to incur stress-related injuries to their wrists. This problem is significant to their performance, and controllers use a different set of muscles. For somebody that plays the game 40+ a week, increased comfort leads to a more stable performance.
Combine that with the fact that most pro-scene fights play out in midrange (where aim-assist shines), the fact that pros absolutely know how to abuse every advantage in their setup, and the fact that some of the M&K specific exploits are banned in ALGS (tap-strafing for example), and you get an environment which specifically nerfs M&K and a lot of people that know how to abuse controller specific advantage.
