He has had 4 awpers in his career and all of them were good even though Mantuu was more a rifler before joining OG and m0nesy & headtr1ck were both rookies in tier 1.
Also it's not like he didn't let m0nesy do anything, actually m0nesy was involved in more opening duels in the 86 maps he played with Aleksib (473 opening duels) than he has been in the last 88 maps with HooXi as his IGL (459 opening duels). Opening duels aren't ofc everything, but he did take more of those under Aleksib as the IGL.
Yes he might not be the best at using awpers, but none of the awpers he has had have been bad either meaning he isn't as terrible at using them as people say. It's not like in for example Liquid where oSee's stats have really been bad. headtr1ck got 1,10 rating this year, mantuu under Aleksi had 1,13 rating and m0nesy also with 1,12 rating. He could use them more freerly, but I guess he thinks it's in many cases better to have the awper hold some angle while riflers do the work which is understandable especially in his last 2 teams where there have been strong riflers (at least when they are on form) like NiKo, Hunter, Rez, hampus, Brollan & k0nfig, all players that can go first without needing to risk the awper.
I think you underestimate the impact of simple experience m0nesy has gotten after the first half of 2022, just as a reminder he was playing tier 1 for the first time and also communicating in English in a team for the first time. He is obviously getting more comfortable and thus getting more consistency and all-around better. Also he is still very young so he is bound to get better as time goes on.