Did a quick look and unless I miscounted there were a total of 171 new videos in 2024 (regular episodes, so not counting complete series, best ofs, merch announcements, or one off videos like the Eggman won ai song.) and Zach was in a whopping 15 total (8.7%). Most of which were from Boneyplays this year. For comparison, Chris' Irish friend Paddy was in 9 videos this year, and he was just visiting.
I get that he's busy with Smiling Friends but still, for an ostensibly "main" cast member (they know to put him on every best of thumbnail to increase views) that's a pretty weak showing. I wonder if Zach has been trying to separate himself from Oneyplays for one reason or another? I doubt that personally but it sure feels like he doesn't want to be on the show much anymore.