Oh for heaven's sake, yes - you can still target individual YouTube channels. Just don't let the interface spook you. stick with "Video Views" or the "Video" campaign subtype. that's the only way to keep the "Placements" tab alive so you can pin those channels like a desperate stalker (but, you know, a professional one).
Sure, on a Video Views campaign, Google Ads will still report conversions and outbound clicks tied to your GA4/GTM account - it just won't optimise bids for them. so you'll see the data, but the algorithm won't suddenly care about a purchase event. To actually track those outcomes, get your UTM parameters encoded properly (yes, that means double checking your URL tagging). Then in your Ads columns, add "Conversions," "All Conv.," and "Click-through Conv." Once your GA4 events fire, the numbers show up there.
It's a faff, but it's not dead. Yet