Here's my take (as someone that uses both inputs on PC, depending on the day):

• Consistency is key. It's much more difficult to be in "demon mode" consistently on M&K, especially in CQC, every single time you play. AA allows for much more consistent gameplay.
• When people often refer to "point & click", they think of twitchier games such as CS:GO or Valorant, that basically have one-dimensional aiming without HOLD to ADS. I've played FPS games since the mid-2000s, and Apex & Warzone by far have the hardest tracking that I've encountered, especially when HOLD to ADS is paramount to playing the game fluidly due to the movement mechanics (more so in Warzone). HOLD to ADS, IMO, creates additional tracking difficulties (you can check out some YT videos on this topic).
• Visibility. This is one thing that's never discussed when it comes to controller vs M&K. IMO, the game still suffers from horrible visibility regardless of filters & FOV, and AA helps to reduce some of that reaction time in CQC that's delayed due to visibility. What do I mean by that? You waste reaction time on spotting someone due to visibility and then have to also react in an instant by correctly placing your crosshair on them. AA takes some of that out of the brain equation and significantly lowers your margin of error, especially if your target is moving and rotational AA kicks in. This is all further amplified by playing in 120 FOV on M&K since targets are smaller. Somewhat applies to Caldera long-range fights as well, since the visual noise from terrain at range can really screw up your M&K tracking, so the slightest AA slowdown can keep your brain on target.
• Movement. This is going to be an odd one, and maybe does not tie in to AA per se, but some people on M&K will never achieve controller level of movement because they can't use their left pinky finger due to anatomical reasons to crouch / slide cancel via Ctrl or Caps Lock (most optimal for finger placement, allowing all 5 fingers on WASD, crouch, & jump at the same time). So, you have much better movement coupled with the confidence of rotational AA having a soft lock on as soon as you outmaneuver your target.