I see the Product Owner role the most critical for the success of Scrum in general. This is for PO's simple yet not given properties - vision about the product,

I see the Product Owner role the most critical for the success of Scrum in general. This is for PO's simple yet not given properties - vision about the product, vision of success, and the ability to express this. Everybody else in Scrum is depended on the PO's abilities. One can train to improve the expression and prioritization skills, but it's very hard to train to develop or (even to appropriate) a vision about the product and the success. This becomes even more acute in corporate environment, most PO are recast from former Project or Product Managers, who by definitions are Managers, not visionaries, nor intended customers of the product. As a result, that critical element - the product vision - simply cannot be shared. It's just another "Quarterly Goal" in disguise - "the stonk must up!". So the corpo-Scrum has a greater chance to devolve into shared lack of vision and collaboration theater. One could paraphrase "Show me your PO, and I will tell what your Scrum is".