TBH stewart 2 kill grim and fallen were never truely the main plague of liquid.
On a serious note liquid has a massive issue with their approach to the game, and overall mentality. (overall in regards to practice and grind this has been on going for years at this point)
Using data from hltv.org/news/35389/how-trading-stats-ca..
I suspect that a big issue currently is how they have their anchors and star players utilized and placed out on the map and how they utilize Osee within that structure.
In the past, as was the case with the grandslam roster, their rifler heavy focus and anti strats worked well and when they had consistent riflers it was a beautiful sight to see. Hell they had nitro as their awp/hybrid.
However without the firepower that roster had its been downhill since they lost berlin, and with the current roster they are still trying to apply that same game plan despite having a dedicated awper and far worse star and firepower overall.
liquid needs to adopt a better type of system to account for this or they will continue to spiral, such examples would be that of Faze/Vitality/Heroic personally I think if they can incorporate heroic's style of play into their structure they may find better success