Sorry but YouTube is not a far more potent vector.
Facebook and Zuckerberg were fairly blamed because they actively developed features that amplified misinformation, and refused to take any action to curb their damage.
We've seen many articles over the last few years about the YouTube recommendation rabbit hole radicalizing young people online. Facebook is not blameless, but they've become a scapegoat for issues plaguing an entire industry.
"Facebook is a potent vector for misinformation" doesn't disprove the contention that YouTube is a more potent vector. We're aware of Facebook's issues around this largely because Facebook became the de facto representative for Everything Wrong With Big Tech -- and while there's a solid case to be made that it's their own damn fault they're in that position, it's kept documented problems with other platforms out of the spotlight. YouTube's recommendation algorithm is notorious for leading you to ever-more extremist ("high engagement!") takes on a variety of topics. And in some high-profile cases -- for instance, Alex Jones back in 2018, coronavirus vaccine disinformation just this year -- YouTube was well behind other social media platforms in executing bans. There is an arguable case to be made that compared to YouTube, Facebook is a relative model of responsibility.
(And, yes, there's a larger question about how companies like YouTube and Facebook should be approaching moderation at all, who gets to decide what is and isn't misinformation, who watches the watchmen, etc. But if we presume there's a rationale for moderation at all, then YouTube should be getting way more scrutiny than it generally receives.)