From Roku's blog post, it seems that Google wants a dedicated area in the global search for YouTube results. For example, If you search for "Last Week Tonight", Google wants a YouTube results row showing clips on their service above results from other content platforms like HBO Max. Basically, Google wants to have the placement that search ads get on their platform on Roku.
Previous Roku complaints about Google have included that Google wants all Roku devices to support the AV1 codec - which Google's own Chromecast with Google TV doesn't support.
I think the "dumb and twisted" goes both ways. It's dumb and twisted that Google won't allow Roku devices to run YouTube if Roku doesn't commit that all future Roku devices support AV1 - when even Google's own streaming device doesn't support AV1. It's dumb and twisted that Google wants a dedicated row for YouTube search results rather than neutral search results.