yeah i understand, the issue IMO is that aim trainers don't utilize movement like CS GO's movement, so in-game you still fuck up your shots because maybe your precision or whatever has gotten a little better w/ aim trainers but they don't train the dynamic that is movement+aiming like DM does. just something to keep in mind. DM has never been beaten in terms of direct correlation to shooting in CS GO, because it is CS GO.
some other things you can try in DM to improve your aim include: using pistols when everyone else is using rifles (really forces you to work on evasive movement and precise aim), using a scout when everyone else is using rifles (forces you to aim at the head because one missed shot and you're probably dead), holding angles (yes it may be lame but it's an important part of the game), prefiring (hear footsteps around a corner, so you strafe out+counter-strafe+shooting), and practice shooting while ADADADADing around a corner at far away enemies. if they stay in one spot and try to hit you, you almost always win that fight w/ the deagle.
did you know you can take a gun like the m4a4, run around, see an enemy, and you can hit ADADADAD while tapping at the exact right time w/ each change of direction and almost every bullet will be accurate? if you get good at it you can literally "spray" (fast tap) the m4a4 while ADADADing and you can kill the enemy with just a few taps. you can also experiment with stuff like combining tapping and spraying, some work better than others depending on gun and distance, like 2 taps+spray, or short spray+tapping, etc, every combination you can think of, because some actually are better than pure tapping or pure spraying.
with creativity there's endless shit you can practice in DM and improve your aim.