Well, for a lot of realism or immersion themed games, its basically taken as a given that reticles are not realistic, that blind firing a weapon is inaccurate, and that ADS should provide an benefit to accuracy whilst usually lowering movement speed and taking a bit to bring up the weapon.

Thats kind of the whole debate back in the early/mid 2000s that led to ADS becoming a thing, but with time, ADS has basically become an expected feature, even if the core mechanics underlying it are now neutered to the point that it is practically cosmetic only.

One solution I can see is doing something like what Arma does, but more immersively, more thought through.

In Arma, your point of viewing is not connected directly to your point of aim. You can look over your shoulder, fire, and the gun will fire at the vector it is pointing, not where your eyes are pointing.

What you could do is make it so that instead of your arms and the gun be pointing directly ahead at all times... they wander about the screen independent of your center of the screen, dependent on your level of woundedness and exhaustion, so that you have a visual indicator of unsteadyness... which is what blooming and closing aiming reticles were originally meant to convey, as 90s FPSs didnt have the technical ability to do that kind of animation.

You could also make it so that the weapon aiming vector chases the eye aiming vector on a delay, and that would go to significant lengths to cut down on the twitch shooter kind of thing where you can do a 180 and basically instantly be on target, cut down on the video gamey ness of many fast paced shooters.

With modern tech its also totally possible to make it so that if you are shot in the arm, maybe you drop your gun, or if shot in the leg, maybe you collapse. It is usually the case that this only happens to NPCs, but never players.

Ive made mods toying with this in Source over a decade ago now, and it was possible then, just the animations were janky as fuck from the viewpoint of anyone who is not the player.

Now we have motion matching doable in Unity and UE5 and that could absolutely make the animations look far better.

One element of online shooters is basically silly animations for a player with high mouse sensitivity doing a 180 and this basically results in them just instantly pierroutting, not needing to take steps and reshoulder the gun. With motion matching and my vector chasing idea, you can make it so there are actually fluid, believable animations, and thus penalties, for doing said 180.

Maybe some day I will be able to mock this up... kind of hard to do game dev with no real internet access (posting on 4g lol)