Difficulty transferring aim ability to certain games. Any tips?

I switched to MnK from controller in December, so I've been aiming with a mouse for about 4 months, aim training for an hour almost every day. It is clear to me that my aim has improved a lot in kovaaks and in game as well to some extent. However, I've noticed that I find it much more difficult to aim in my main game (Apex Legends) compared to other games like Quake Champions. I feel like I am so much more consistent in Quake and that aim training transfers over very well to that game.

Now, I know the obvious thing is that Quake doesn't have recoil and Apex does (albeit very little), but even so, the movement speed in apex is slower than quake and I still miss way more shots in Apex on comparatively easier enemies to hit.

I have a few theories about why this may be happening, but I am also curious if there is anyone else here that finds they have this same problem in Apex or certain games.

My theories include:

  1. In apex, if you die it's over. You go back to the lobby. I feel I get way more nervous and panicked in gunfights in Apex because of the one-life nature of the matches. In quake, I can run around like a chicken with it's head cutoff and still just spawn in again. Maybe I tense my arm in Apex more?
  2. I find enemies in Apex sometimes difficult to visually track. The character models really don't stand out well against certain backdrops. In Quake, the enemy glows red the whole time and there is no ironsight or weapon blocking my view.
  3. I get significantly less practice aiming in Apex due to the nature of it being battle royale. Maybe I just lack practice aiming in that game?

Any help/advice/tips are welcome. Sorry if this isn't really the best place to ask these questions. I've never posted here before but didn't know where else to turn.

Edit: So I was playing some kovaaks and Apex again last night and I tried turning anti-aliasing on. This (as well as some of the other kovaaks scenario recommendations received here) seems to have helped my ability to visually track enemies in game. I guess I didn't make this clear in my original post, but it's my ability to visually track enemies in Apex that I sometimes struggle with. I guess with this post I was more wondering if there were any other aim enthusiasts that struggle with going from kovaaks (i.e. very easily discernible enemies) to certain games like Apex where the enemies don't have super stark contrast. But thank you to everyone that offered advice and encouragement.