Isometric drawings of real world objects have universal appeal and that makes them a good choice of style when systems need to be explained. Essentially a schematic, this gas piping system has been created as a bright, colourful isometric for use in staff training.
The ability to include cross sections, cut-aways, and artificial geography while creating objects that are recognisable is part of the versatility of this type of diagram.
The same content could be represented in a flow chart but it would lose the engagement that comes from recognising objects.
Choosing the right visualisation tool for each application requires an understanding of how the diagram is to be used and knowledge of the level of existing understanding that the audience brings to the occasion.