Despite the title being about YouTube, this is fundamentally about Safari's declarative Content Blocker API being totally inadequate in the face of modern ad delivery technologies. Yes, it's fast and relatively more secure compared to old ad blocking techniques (which requires granting full access to effectively arbitrary JS), but ad tech has evolved since 2015 and Safari's Content Blocking API has not evolved with it.
With other browsers showing varying degrees of interest in declarative content blocking, it's worth looking at Safari as a warning of what declarative content blocking, if unmaintained, will do to cripple ad blocking for users.
With other browsers showing varying degrees of interest in declarative content blocking, it's worth looking at Safari as a warning of what declarative content blocking, if unmaintained, will do to cripple ad blocking for users.