"... but impossible to use domain-based adblock like pi-hole since both ads and content are served through the same Google domain."

However, ads and video are not served through the same Google domain.

Further, the ads are not served unless Javascript is enabled.

As such, aside from user comments, it is easy to retrieve the non-video content without retrieving the ads. Just use an HTTP client that ignores Javascript.

Javascript is not needed to view video from the domains that serve the video.