u get out what u put in imo
knowing about the holes in ur gameplay (ie. poor click timing, shaky tracking, etc) and playing specific scenarios that
focus on those is a good way to overcome ur weaknesses. i definitely noticed a considerable improvement in my aim and consistency when i was rlly grinding kovaaks, id highly recommend it. that being said there are definitely some scenarios that are more beneficial then others, so id also recommend doing some research beforehand (theres plenty of guides out there that are a good place to start) and playing around to see what works best for u.
obviously this is all just from my personal experience, aiming is personal and there is no universal way to "git gud".
also kovaaks > aimtastic
kovaaks has an infinite amount of scenarios to try, and in my experience the aimtastic ones aren't that great