Model-Based Systems Engineers, particularly those moving from software to systems engineering, claim that SysML-like notations, which are symbolic two-dimensional diagrams made of boxes and lines, are domain-independent, thus very convenient to support the cross-functional design of a system architecture. However, the abstract diagramming syntax of MBSE notations makes their adoption difficult, especially by notational nonexperts, and using iconic graphics is one way of improvement. Very few studies attempted to replace 2D diagrams with immersive 3D visuals without objective evidence. We assume that it is due to a lack of quality criteria to compare 2D diagrams with 3D visuals. This paper will argue that human-centric 3D visuals should replace MBSE diagrams where appropriate. A new human-centric MBSE modelling environment motivates the adoption of interactive and immersive 3D visuals to facilitate communication and participation in multidisciplinary co-design activities from mission to concept definition. Our claim is not supported by measured evidence, but a functional demonstrator provides observed evidence and, compared to existing studies, we discuss our proposal based on the Physics of Notation. Future studies will concentrate on the modelling of the behavioural and structural views and the definition of criteria to validate the human-centric MBSE modelling environment.